Chapter 5 Matter in Motion
Motion <ul><li>When an object changes distance over time.  </li></ul><ul><li>How do you know if an object is in motion? </...
Reference point <ul><li>Is an object that motion is measured against </li></ul><ul><li>What is the reference point in this...
Frame of Reference Video 1960
Speed Formula  ex. 66m/s <ul><li>AS=Average </li></ul><ul><li>Speed </li></ul><ul><li>TD=Total </li></ul><ul><li>Distance ...
Average Speed Actual Speed
 
Solve for AS, TT, or TD <ul><li>If you walk for 1.5 hours and travel 7.5 km what is your average speed? </li></ul><ul><li>...
Solve for AS, TT, or TD <ul><li>If you ride a bike .5 hours and cover 4,000 m what is your average speed?  </li></ul><ul><...
Solve for AS, TT, or TD <ul><li>If the average speed of a car is 110 km/hr how long will it take that car to travel 715 km...
Solve for AS, TT, or TD <ul><li>If the average speed of a tricycle is 5 km/hr what distance will it cover in 10 hours? </l...
Velocity Formula  ex. 66m/s West <ul><li>V= Velocity </li></ul><ul><li>TD=Total </li></ul><ul><li>Distance </li></ul><ul><...
Velocity- Speed in a given direction  west (m)
Combining Velocity When you combine two velocities that are  in the same direction,  add them together to find the resulta...
Combining Velocity When you combine two  velocities that are  in opposite directions,  subtract the smaller velocity from ...
Combining Velocity <ul><li>What happens when the person and the bus go in the same direction? </li></ul><ul><li>__________...
Look at p. 110 and complete the self check.  <ul><li>___________________________________ </li></ul><ul><li>_______________...
How do we measure a change in velocity?  What is a change in velocity called?  <ul><li>Acceleration-  The rate at which ve...
 
Acceleration Formula <ul><li>∆  = change </li></ul><ul><li>Acceleration =  ∆ V ∆ V= Final V- Starting V   </li></ul><ul><l...
Units for Acceleration <ul><li>* Sample Problem: What is the acceleration if we speed up from 10 Km/h to 30 km/hr in 10 se...
<ul><li>1. A plane passes over point A with a velocity of 8000 m/s north. Forty seconds later it passes over point B with ...
<ul><li>2. A coconut falls from the top of a tree and reaches a velocity of 19.6 m/s when it hits the ground.  It takes tw...
 
 
 
 
1 2 3
1 2 3 4 5
1 2 3 4 5
1 2 3 4 5
Time (s) Time (s) Velocity (m/s) Position (m)
Time (s) Time (s) Velocity (m/s) Position (m)
C
D T D D S A T A T S D A 12.  ______3 Km/hr/sec 9.  ______25ft 6.  ____150mph 3. _____34 min 11. ______6 cm/min/sec 8.  ___...
13. Goldie Goldfish, a speed swimmer, loves to race around the park’s pond, which is 0.5 miles around. If she can swim 20 ...
14. It takes Stu, a slimy slug, 20 minutes to travel from his favorite bush to the local trash can (a trip of 30m), how fa...
15. At exactly 2:00 pm, Speedy the Snail crawls onto a meter stick at the 10 cm mark. If he reaches the 65 cm mark at exac...
16. If it takes Leaping Louie 5 minutes to jump 3 blocks, how long will it take for him to jump 15 blocks? <ul><li>What is...
16. If Bert the Bat travels eastward at 40 mph with a tail wind of 6 mph, what is his actual speed? <ul><li>Don’t use a fo...
18. Toon Train is traveling at the speed of 10 m/s at the top of a hill. Five seconds later it reaches the bottom if the h...
19. Pete the Penguin loves to sled down his favorite hill. If he hits a speed of 50 m/s after 5 seconds, what is his rate ...
20. Monster Mike’s truck decelerates from 72 m/s to 0 m/s in 6 seconds. What is his rate of deceleration? <ul><li>Accelera...
Quick Review  <ul><li>What does A show for distance/time? </li></ul><ul><li>What does B show for distance/time?  </li></ul...
Quick Review  <ul><li>What does A show for velocity /time? </li></ul><ul><li>What does B show for velocity /time? </li></u...
Speed and Acceleration Part 1: <ul><li>Does the speedometer of a car read average speed or instantaneous speed?  </li></ul...
Speed and Acceleration Part 1: <ul><li>If the speedometer of your car reads a constant speed of 40km/hr, can you say the c...
<ul><li>a)  Which two controls on a car cause a change in speed?  </li></ul><ul><li>_________________________ </li></ul><u...
<ul><li>What is the acceleration of a car that travels in a straight line at a constant speed?  </li></ul><ul><li>________...
Part 2: Calculations 6. It takes Serina 0.25 hours to drive to school. Her route is 16 km long. What is Serina’s average s...
Part 2: Calculations 7. In a competition, an athlete threw a flying disk 139 meters through the air. While in flight, the ...
Part 2: Calculations 8. A runner covers the last straight stretch of a race in 4 s.  During that time, he speeds up from 5...
Part 2: Calculations 9.  If you shout into the Grand Canyon, your voice travels at the speed of sound (340 m/s) to the bot...
Part 2: Calculations 10. Falling objects drop with an average acceleration of 9.8 m/s2.  If an object falls from a tall bu...
Part 2: Calculations 11.  Josh rolled a bowling ball down a lane in 2.5 s.  The ball traveled at a constant acceleration o...
Acceleration Practice: Part 1: True or False <ul><li>1. _______ If you slow down on your bike you accelerate? </li></ul><u...
Acceleration Practice: Part 2: Acceleration? <ul><li>4. You are riding your bike at  </li></ul>
 
Force 5-2 p. 115 - 118 <ul><li>Force is a push or a pull </li></ul><ul><li>Forces have the ability to change an objects mo...
<ul><li>Forces may change an objects shape </li></ul><ul><li>Forces give  energy  to an object </li></ul><ul><li>All of th...
 
<ul><li>Unbalances Forces: are unequal forces  </li></ul><ul><ul><li>Some change in movement occurs </li></ul></ul><ul><ul...
Left
<ul><li>What is the motion of this object? </li></ul><ul><li>Are the forces balanced? </li></ul>
<ul><li>Forces can be represented with arrows called  vectors .  </li></ul><ul><ul><li>Vectors show the direction and magn...
Chapter 5 Section 3  <ul><li>Friction  is a force that opposes motion between surfaces that are touching.  </li></ul><ul><...
On p. 119
Two ways to  Increase  friction. <ul><li>1. Make the surface rougher. </li></ul><ul><li>2. Greater force. </li></ul>
Two ways to  Decrease  friction. <ul><li>1. Make the surface smoother. </li></ul><ul><li>2. Less force. </li></ul>
 
Be Careful!  <ul><li>Friction is not increased by increasing surface area if the mass stays constant.  </li></ul>
Types of friction <ul><li>Sliding </li></ul><ul><li>Rolling </li></ul><ul><li>Fluid </li></ul><ul><li>Static </li></ul>
Examples of types of Friction <ul><li>Sliding </li></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____...
Examples of types of Friction <ul><li>Rolling </li></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____...
Examples of types of Friction <ul><li>Fluid- Remember this is a liquid or a gas! </li></ul><ul><ul><li>___________________...
Examples of types of Friction <ul><li>Static- friction with no movement but a force is applied. </li></ul><ul><ul><li>____...
Explain this diagram.
5-4 Gravity Section 5-4
5-4 Gravity <ul><li>Gravity: force of attraction between objects due to their masses.  </li></ul><ul><li>Why are astronaut...
<ul><li>Gravity acts “down”.  Earth gravity pulls objects towards the center of the Earth. So no matter where you are on E...
<ul><li>What do the apple and the moon have in common? </li></ul><ul><li>The law of universal gravitation.  </li></ul><ul>...
Small mass, Small distance= Medium Gravity Large mass, Small distance= Large Gravity Large mass, Large distance= Small Gra...
If all objects have gravity why don’t you feel it?  <ul><li>Earth is so big and close that all other things are very small...
Weight V.S. Mass  <ul><li>What does this diagram show? </li></ul>
Weight V.S. Mass <ul><li>Our mass is in Kilograms but our weight is in Newtons…. Why? </li></ul><ul><li>Weight is the forc...
Weight V.S. Mass on Earth <ul><li>Using the data below, explain the relationship between  weight and mass on earth? </li><...
What is the formula for weight? WEIGHT  (N) MASS (Kg) Acceleration DUE TO GRAVITY (on earth  9.8 m/s/s)
Weight Mass <ul><li>Balance </li></ul><ul><li>Measure of gravity </li></ul><ul><li>Constant on earth </li></ul><ul><li>Mea...
Directed Reading 5-2 <ul><li>1. All forces have size and direction True / False </li></ul><ul><li>2. A force is a push or ...
<ul><li>6. In which of the following situations is a force being exerted?  </li></ul><ul><li>A. A woman pushes the elevato...
Directed Reading 5-2 <ul><li>8. Suppose the dog on the left in figure 9, on page 117, increased its force to 13 N. Which d...
Directed Reading 5-2 <ul><li>11. To start or change the motion of an object you need a (n) __________ force. </li></ul><ul...
Directed Reading 5-3 <ul><li>1. What force is responsible for the painful difference between sliding on grass and sliding ...
Directed Reading 5-3 <ul><li>4. Why is more force needed to slide the larger book in Figure 12 on p. 120?  </li></ul><ul><...
Directed Reading 5-3 <ul><li>6. Hockey puck on ice </li></ul><ul><li>7. Crate on loading ramp </li></ul><ul><li>8. Wheeled...
Directed Reading 5-3 <ul><li>10. Static friction is at work if you try to drag a heavy suitcase along the floor and the su...
<ul><li>12. How does friction harm the engine of a car?  </li></ul><ul><li>___________________________________ </li></ul><...
Section Review p. 124 <ul><li>1. Explain why friction occurs? </li></ul><ul><li>2. Name two ways friction can be increased...
Directed Reading 5-4 <ul><li>1. Why did the astronaut in Figure 18 bounce on the moon?  </li></ul><ul><li>2. The force of ...
Directed Reading 5-4 <ul><li>5. Do scientists think that seeds can sense gravity? True  /  False </li></ul><ul><li>6. Sinc...
Directed Reading 5-4 <ul><li>8. What did Newton find out about the moon and the falling apple?  ________________ </li></ul...
Directed Reading 5-4 <ul><li>11. If the distance between objects are the same the gravitational force between two feathers...
Directed Reading 5-4 <ul><li>14. In a _____________ gravity is so great that even light can’t escape.  </li></ul><ul><li>1...
<ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ ...
Section Review p. 129 <ul><li>1. How does the mass of an object relate to the gravitational force the object exerts on oth...
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Chapter 5

  1. 1. Chapter 5 Matter in Motion
  2. 2. Motion <ul><li>When an object changes distance over time. </li></ul><ul><li>How do you know if an object is in motion? </li></ul>
  3. 3. Reference point <ul><li>Is an object that motion is measured against </li></ul><ul><li>What is the reference point in this picture. </li></ul>
  4. 4. Frame of Reference Video 1960
  5. 5. Speed Formula ex. 66m/s <ul><li>AS=Average </li></ul><ul><li>Speed </li></ul><ul><li>TD=Total </li></ul><ul><li>Distance </li></ul><ul><li>TT=Total </li></ul><ul><li>Time </li></ul>
  6. 6. Average Speed Actual Speed
  7. 8. Solve for AS, TT, or TD <ul><li>If you walk for 1.5 hours and travel 7.5 km what is your average speed? </li></ul><ul><li>AS = TD </li></ul><ul><li> TT </li></ul><ul><li>AS = 7.5 km </li></ul><ul><li> 1.5 hr </li></ul><ul><li>AS = 5 km/hr </li></ul>
  8. 9. Solve for AS, TT, or TD <ul><li>If you ride a bike .5 hours and cover 4,000 m what is your average speed? </li></ul><ul><li>AS = TD </li></ul><ul><li> TT </li></ul><ul><li>AS = 4,000 m </li></ul><ul><li> .5 hr </li></ul><ul><li>AS = 8,000 m/hr </li></ul>
  9. 10. Solve for AS, TT, or TD <ul><li>If the average speed of a car is 110 km/hr how long will it take that car to travel 715 km? </li></ul><ul><li>TT = T D </li></ul><ul><li> AS </li></ul><ul><li>TT = 715 km </li></ul><ul><li> 110 km/hr </li></ul><ul><li>TT = 6.5 hr </li></ul>
  10. 11. Solve for AS, TT, or TD <ul><li>If the average speed of a tricycle is 5 km/hr what distance will it cover in 10 hours? </li></ul><ul><li>TD = AS * TT </li></ul><ul><li>TD = 5 km/hour * 10 hours </li></ul><ul><li>TD = 50 km </li></ul>
  11. 12. Velocity Formula ex. 66m/s West <ul><li>V= Velocity </li></ul><ul><li>TD=Total </li></ul><ul><li>Distance </li></ul><ul><li>TT=Total </li></ul><ul><li>Time </li></ul>+ direction
  12. 13. Velocity- Speed in a given direction west (m)
  13. 14. Combining Velocity When you combine two velocities that are in the same direction, add them together to find the resultant velocity.
  14. 15. Combining Velocity When you combine two velocities that are in opposite directions, subtract the smaller velocity from the larger velocity to find the resultant velocity. The resultant velocity is in the direction of the larger velocity.
  15. 16. Combining Velocity <ul><li>What happens when the person and the bus go in the same direction? </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>What happens when the person and the bus are going in different directions? </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul>
  16. 17. Look at p. 110 and complete the self check. <ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul>
  17. 18. How do we measure a change in velocity? What is a change in velocity called? <ul><li>Acceleration- The rate at which velocity is changing. </li></ul><ul><ul><li>Term “Acceleration” is used when velocity increases. </li></ul></ul><ul><ul><li>Term “Deceleration” is used when velocity decreases. </li></ul></ul><ul><ul><li>A “change in direction” but not speed is also acceleration. </li></ul></ul>
  18. 20. Acceleration Formula <ul><li>∆ = change </li></ul><ul><li>Acceleration = ∆ V ∆ V= Final V- Starting V </li></ul><ul><li>t </li></ul><ul><li>Acc.= Final V - Starting V </li></ul><ul><li> t </li></ul>
  19. 21. Units for Acceleration <ul><li>* Sample Problem: What is the acceleration if we speed up from 10 Km/h to 30 km/hr in 10 seconds? </li></ul><ul><li>Acceleration = ∆ V = 30 km/hr - 10km/hr </li></ul><ul><li>t 10 sec </li></ul><ul><li>Acceleration = 2 km/hr/s </li></ul>
  20. 22. <ul><li>1. A plane passes over point A with a velocity of 8000 m/s north. Forty seconds later it passes over point B with a velocity of 10,000 m/s north. What is the planes acceleration from A to B? </li></ul><ul><li>Acceleration = ∆ V 10,000 m/s – 8,000 m/s </li></ul><ul><li>t 40 s </li></ul><ul><li>Acc= 50 m/s/s or m/s 2 </li></ul>
  21. 23. <ul><li>2. A coconut falls from the top of a tree and reaches a velocity of 19.6 m/s when it hits the ground. It takes two seconds for the coconut to hit the ground. What is its acceleration? </li></ul><ul><li>Acceleration = ∆ V 19.6 m/s – 0 m/s </li></ul><ul><li>t 2 s </li></ul><ul><li>Acc= 9.8 m/s/s or m/s 2 </li></ul>
  22. 28. 1 2 3
  23. 29. 1 2 3 4 5
  24. 30. 1 2 3 4 5
  25. 31. 1 2 3 4 5
  26. 32. Time (s) Time (s) Velocity (m/s) Position (m)
  27. 33. Time (s) Time (s) Velocity (m/s) Position (m)
  28. 34. C
  29. 35. D T D D S A T A T S D A 12. ______3 Km/hr/sec 9. ______25ft 6. ____150mph 3. _____34 min 11. ______6 cm/min/sec 8. ______3.2 s 5. ____12cm/s 2 2. _____30 m/s 10. ______1.4 m 7. ______ 14mi 4. ______ 6 hr 1. ______14km
  30. 36. 13. Goldie Goldfish, a speed swimmer, loves to race around the park’s pond, which is 0.5 miles around. If she can swim 20 laps around the track in 2 hours, what is her average speed? <ul><li>What is missing? </li></ul><ul><li>20 * 0.5 = 10 mi </li></ul><ul><li>AS= TD/TT </li></ul><ul><li>10mi / 2 hr </li></ul><ul><li>AS= 5 mph </li></ul>
  31. 37. 14. It takes Stu, a slimy slug, 20 minutes to travel from his favorite bush to the local trash can (a trip of 30m), how far can he travel in 1 hour (60 min)? <ul><li>What is the first step. </li></ul><ul><li>AS= TD/TT </li></ul><ul><li>30 m / 20 min </li></ul><ul><li>AS= 1.5 m / min </li></ul><ul><li>Now what? </li></ul><ul><li>S * T = D </li></ul><ul><li>1.5 m / min * 60 min = 90m </li></ul>
  32. 38. 15. At exactly 2:00 pm, Speedy the Snail crawls onto a meter stick at the 10 cm mark. If he reaches the 65 cm mark at exactly 2:10 pm, what is his speed? <ul><li>What is the first step. </li></ul><ul><li>65cm -10cm= 55cm (which is the total distance) </li></ul><ul><li>Now what? </li></ul><ul><li>AS= TD/TT </li></ul><ul><li>AS= 55cm /10 min </li></ul><ul><li>AS= 5.5 cm / min </li></ul>
  33. 39. 16. If it takes Leaping Louie 5 minutes to jump 3 blocks, how long will it take for him to jump 15 blocks? <ul><li>What is the first step. </li></ul><ul><li>3 blocks / 5 min = .6 blocks / min </li></ul><ul><li>Now what? </li></ul><ul><li>15 / .6 block / min = 25 min </li></ul>
  34. 40. 16. If Bert the Bat travels eastward at 40 mph with a tail wind of 6 mph, what is his actual speed? <ul><li>Don’t use a formula just think about it! </li></ul><ul><li>Add the bat’s velocity to the wind’s 46 mph </li></ul>6mph east 40 mph east
  35. 41. 18. Toon Train is traveling at the speed of 10 m/s at the top of a hill. Five seconds later it reaches the bottom if the hill and is moving at 30 m/s. What is the rate of acceleration of Toon Train? <ul><li>Acceleration = ∆ V </li></ul><ul><li>t </li></ul><ul><li>30m/s – 10 m/s = </li></ul><ul><li>5 s </li></ul><ul><li>Acc= 4 m/s/s down </li></ul>
  36. 42. 19. Pete the Penguin loves to sled down his favorite hill. If he hits a speed of 50 m/s after 5 seconds, what is his rate of acceleration? Hint: He starts at 0 m/s at the top of the hill. <ul><li>Acceleration = ∆ V </li></ul><ul><li>t </li></ul><ul><li>50m/s – 0 m/s = </li></ul><ul><li>5 s </li></ul><ul><li>Acc= 10 m/s/s down </li></ul>
  37. 43. 20. Monster Mike’s truck decelerates from 72 m/s to 0 m/s in 6 seconds. What is his rate of deceleration? <ul><li>Acceleration = ∆ V </li></ul><ul><li>t </li></ul><ul><li>0m/s – 72 m/s = </li></ul><ul><li>6 s </li></ul><ul><li>Acc= -12 m/s/s forward </li></ul>
  38. 44. Quick Review <ul><li>What does A show for distance/time? </li></ul><ul><li>What does B show for distance/time? </li></ul><ul><li>What does C show for distance/time? </li></ul>Time (min) Distance (km)
  39. 45. Quick Review <ul><li>What does A show for velocity /time? </li></ul><ul><li>What does B show for velocity /time? </li></ul><ul><li>What does C show for velocity /time? </li></ul>Time (min) Velocity (km/ min east)
  40. 46. Speed and Acceleration Part 1: <ul><li>Does the speedometer of a car read average speed or instantaneous speed? </li></ul><ul><li>______________________________ </li></ul><ul><li>How do you know? </li></ul>Instantaneous It shows the speed you are going right now, not the speed you were going or are going to go. It also changes as you push the gas.
  41. 47. Speed and Acceleration Part 1: <ul><li>If the speedometer of your car reads a constant speed of 40km/hr, can you say the car has a constant velocity? ______ </li></ul><ul><li>Explain your answer. </li></ul>No You can’t say this because the car could be changing direction. Ex. Nascar
  42. 48. <ul><li>a) Which two controls on a car cause a change in speed? </li></ul><ul><li>_________________________ </li></ul><ul><li>_________________________ </li></ul><ul><li>b) Which additional control causes a change in velocity? </li></ul><ul><li>_________________________ </li></ul>Gas Pedal Brake Steering Wheel
  43. 49. <ul><li>What is the acceleration of a car that travels in a straight line at a constant speed? </li></ul><ul><li>_________________________________ </li></ul><ul><li>Describe a situation in which you can accelerate even though your speed doesn’t change. </li></ul><ul><li>___________________________________ </li></ul>The acceleration of the car would be 0 m/s/s Pac-man.
  44. 50. Part 2: Calculations 6. It takes Serina 0.25 hours to drive to school. Her route is 16 km long. What is Serina’s average speed on her drive to school? S= D/T S= 16 km .25 hr S= 64 km/hr Answer: Work: Formula:
  45. 51. Part 2: Calculations 7. In a competition, an athlete threw a flying disk 139 meters through the air. While in flight, the disk traveled at an average speed of 13.0 m/s. How long did the disk remain in the air? T=D/V T= 139m 13 m/s T= 10.69 s Answer: Work: Formula:
  46. 52. Part 2: Calculations 8. A runner covers the last straight stretch of a race in 4 s. During that time, he speeds up from 5 m/s to 9 m/s. What is the runner’s acceleration in this part of the race? Acc= V f –V s TT Acc= 9m/s – 5 m/s 4 s Acc.= 1 m / s / s Answer: Work: Formula:
  47. 53. Part 2: Calculations 9. If you shout into the Grand Canyon, your voice travels at the speed of sound (340 m/s) to the bottom of the canyon and back, and you hear an echo. How deep is the Grand Canyon at a spot where you can hear your echo 5.2 seconds after you shout? D=T * V D= 5.2 * 340 D= 1768 m Answer: Work: Formula:
  48. 54. Part 2: Calculations 10. Falling objects drop with an average acceleration of 9.8 m/s2. If an object falls from a tall building, how long will it take before it reaches a speed of 49 m/s? T = V f - V s Acc T= 49 – 0 9.8 T= 5 s Answer: Work: Formula:
  49. 55. Part 2: Calculations 11. Josh rolled a bowling ball down a lane in 2.5 s. The ball traveled at a constant acceleration of 1.8 m/s2 down the lane and was traveling at a speed of 7.6 m/s by the time it reached the pins at the end of the lane. How fast was the ball going when it left Tim’s hand? V s = V f –(A * T) V s = 7.6 m/s – (1.8 * 2.5) V s = 3.1 m/s Answer: Work: Formula:
  50. 56. Acceleration Practice: Part 1: True or False <ul><li>1. _______ If you slow down on your bike you accelerate? </li></ul><ul><li>Why?___________________________________ </li></ul><ul><li>2. _______ If you ride your bike at a constant speed, you cannot accelerate? </li></ul><ul><li>Why?__________________________________ </li></ul><ul><li>3. _______Changing the speed and changing the direction of your bike are both examples of acceleration? </li></ul><ul><li>Why?___________________________________ </li></ul>True False True
  51. 57. Acceleration Practice: Part 2: Acceleration? <ul><li>4. You are riding your bike at </li></ul>
  52. 59. Force 5-2 p. 115 - 118 <ul><li>Force is a push or a pull </li></ul><ul><li>Forces have the ability to change an objects motion </li></ul><ul><ul><li>Starting </li></ul></ul><ul><ul><li>Stopping </li></ul></ul><ul><ul><li>Speeding up </li></ul></ul><ul><ul><li>Slowing down </li></ul></ul><ul><ul><li>Changing direction </li></ul></ul>
  53. 60. <ul><li>Forces may change an objects shape </li></ul><ul><li>Forces give energy to an object </li></ul><ul><li>All of the forces acting on an object together are known as net forces </li></ul><ul><li>Balanced Forces: are equal net forces </li></ul><ul><ul><li>No movement or change in movement occurs </li></ul></ul>
  54. 62. <ul><li>Unbalances Forces: are unequal forces </li></ul><ul><ul><li>Some change in movement occurs </li></ul></ul><ul><ul><li>Where are the unbalanced forces? </li></ul></ul>
  55. 63. Left
  56. 64. <ul><li>What is the motion of this object? </li></ul><ul><li>Are the forces balanced? </li></ul>
  57. 65. <ul><li>Forces can be represented with arrows called vectors . </li></ul><ul><ul><li>Vectors show the direction and magnitude of a force. </li></ul></ul><ul><ul><li>Forces are measured in Newtons (N). </li></ul></ul><ul><ul><li>Larger Force Smaller Force </li></ul></ul><ul><ul><li>MAGNITUDE </li></ul></ul>
  58. 66. Chapter 5 Section 3 <ul><li>Friction is a force that opposes motion between surfaces that are touching. </li></ul><ul><li>Even surfaces that appear smooth have rough edges. </li></ul>
  59. 67. On p. 119
  60. 68. Two ways to Increase friction. <ul><li>1. Make the surface rougher. </li></ul><ul><li>2. Greater force. </li></ul>
  61. 69. Two ways to Decrease friction. <ul><li>1. Make the surface smoother. </li></ul><ul><li>2. Less force. </li></ul>
  62. 71. Be Careful! <ul><li>Friction is not increased by increasing surface area if the mass stays constant. </li></ul>
  63. 72. Types of friction <ul><li>Sliding </li></ul><ul><li>Rolling </li></ul><ul><li>Fluid </li></ul><ul><li>Static </li></ul>
  64. 73. Examples of types of Friction <ul><li>Sliding </li></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul>
  65. 74. Examples of types of Friction <ul><li>Rolling </li></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul>
  66. 75. Examples of types of Friction <ul><li>Fluid- Remember this is a liquid or a gas! </li></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul>
  67. 76. Examples of types of Friction <ul><li>Static- friction with no movement but a force is applied. </li></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul><ul><ul><li>_____________________ </li></ul></ul>
  68. 77. Explain this diagram.
  69. 78. 5-4 Gravity Section 5-4
  70. 79. 5-4 Gravity <ul><li>Gravity: force of attraction between objects due to their masses. </li></ul><ul><li>Why are astronauts so “bouncy on the moon? </li></ul>
  71. 80. <ul><li>Gravity acts “down”. Earth gravity pulls objects towards the center of the Earth. So no matter where you are on Earth all objects fall “down” to the ground. </li></ul>
  72. 81. <ul><li>What do the apple and the moon have in common? </li></ul><ul><li>The law of universal gravitation. </li></ul><ul><li>Describes the relationship between force, mass and distance. </li></ul><ul><li>States that all objects in the universe attract each other through gravitational force. The size of that force depends on the mass of the objects and the distance between the objects. </li></ul>
  73. 82. Small mass, Small distance= Medium Gravity Large mass, Small distance= Large Gravity Large mass, Large distance= Small Gravity
  74. 83. If all objects have gravity why don’t you feel it? <ul><li>Earth is so big and close that all other things are very small or very far making there gravity VERY small. </li></ul><ul><li>The two factors that effect gravity are: </li></ul><ul><li>1. Distance </li></ul><ul><li>2. Mass </li></ul>
  75. 84. Weight V.S. Mass <ul><li>What does this diagram show? </li></ul>
  76. 85. Weight V.S. Mass <ul><li>Our mass is in Kilograms but our weight is in Newtons…. Why? </li></ul><ul><li>Weight is the force of gravity. Forces are measured in Newtons (N) so Weight is measured in Newtons (N). </li></ul>
  77. 86. Weight V.S. Mass on Earth <ul><li>Using the data below, explain the relationship between weight and mass on earth? </li></ul><ul><li>What is the gravity on Earth? </li></ul><ul><li>What is gravity on the Moon? </li></ul>166 N 100kg 980 N 100kg 133 N 80 kg 784 N 80 kg 100 N 60 Kg 588 N 60 Kg Weight Mass Weight Mass Moon Earth
  78. 87. What is the formula for weight? WEIGHT (N) MASS (Kg) Acceleration DUE TO GRAVITY (on earth 9.8 m/s/s)
  79. 88. Weight Mass <ul><li>Balance </li></ul><ul><li>Measure of gravity </li></ul><ul><li>Constant on earth </li></ul><ul><li>Measured in (N) </li></ul><ul><li>Changes with gravity </li></ul><ul><li>6 X less on the moon </li></ul><ul><li>Spring Scale </li></ul><ul><li>Amount of matter </li></ul><ul><li>Constant on earth </li></ul><ul><li>Measured in (g) </li></ul><ul><li>Never changes </li></ul><ul><li>Remains the same when gravity changes </li></ul>
  80. 89. Directed Reading 5-2 <ul><li>1. All forces have size and direction True / False </li></ul><ul><li>2. A force is a push or a pull. True / False </li></ul><ul><li>3. Forces are expressed in liters. True / False </li></ul><ul><li>4. You can exert a push without there being an object to receive the push. True / False </li></ul><ul><li>5. Name three things that you exert a force on while doing your home work? </li></ul>Newtons (N)
  81. 90. <ul><li>6. In which of the following situations is a force being exerted? </li></ul><ul><li>A. A woman pushes the elevator button. </li></ul><ul><li>B. a pile of soil sits on the ground </li></ul><ul><li>C. Socks cling together when they come out of the dryer. </li></ul><ul><li>D. Magnets stick to the refrigerator. </li></ul><ul><li>7. In figure 8 on p. 116 how does the net force help the students move the piano? </li></ul><ul><li>______________________________ </li></ul>Since the forces are in the same direction you add the forces together.
  82. 91. Directed Reading 5-2 <ul><li>8. Suppose the dog on the left in figure 9, on page 117, increased its force to 13 N. Which dog would win the tug-of-war? Explain? </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>9. Why is it useful to know the net force? </li></ul><ul><li>___________________________________ </li></ul><ul><li>10. Forces are unbalances when the net forces are not = to ______________ </li></ul>The dog on the left will win by 1 N because forces are not negative but positive in a direction. It can tell you about the motion of an object. Zero
  83. 92. Directed Reading 5-2 <ul><li>11. To start or change the motion of an object you need a (n) __________ force. </li></ul><ul><li>12. Forces are balanced when the net force applied to an object is ___________ zero. </li></ul><ul><li>13. Are the forces in Figure 10 balanced? ____ How do you know? </li></ul><ul><li>_____________________________________ </li></ul>unbalanced equal to yes The cards are not moving or falling.
  84. 93. Directed Reading 5-3 <ul><li>1. What force is responsible for the painful difference between sliding on grass and sliding on pavement? </li></ul><ul><li>______________________ </li></ul><ul><li>2. Friction occurs when the hills and valleys of two surfaces stick together. </li></ul><ul><li>True / False </li></ul><ul><li>3. Why does pavement create more friction than grass? </li></ul><ul><li>___________________________________ </li></ul>Sliding Friction The pavement is rougher than the grass.
  85. 94. Directed Reading 5-3 <ul><li>4. Why is more force needed to slide the larger book in Figure 12 on p. 120? </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>5. Friction is affected by the amount of the surface that is touching. </li></ul><ul><li>True / False </li></ul>The mass is larger so the downward force That is created is larger.
  86. 95. Directed Reading 5-3 <ul><li>6. Hockey puck on ice </li></ul><ul><li>7. Crate on loading ramp </li></ul><ul><li>8. Wheeled cart pushed </li></ul><ul><li>9. air passing a car </li></ul><ul><li>A. Sliding Friction </li></ul><ul><li>B. Rolling Friction </li></ul><ul><li>C. Fluid Friction </li></ul><ul><li>D. Static Friction </li></ul>
  87. 96. Directed Reading 5-3 <ul><li>10. Static friction is at work if you try to drag a heavy suitcase along the floor and the suitcase (moves or does not move) </li></ul><ul><li>11. As soon as an object starts moving, static friction (increases or disappears). </li></ul>If the suitcase had moved, what type of friction would have been at work?
  88. 97. <ul><li>12. How does friction harm the engine of a car? </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>13. Why do you need friction to walk? </li></ul><ul><li>___________________________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>14. Which of the following will reduce friction? </li></ul><ul><li>A. Use a lubricant. B. Make surface smoother. </li></ul><ul><li>C. Push surfaces D. Change sliding friction </li></ul><ul><li>together. to rolling friction. </li></ul>It wears down the parts inside the car because of sliding friction. If there was no friction you would not be able to grip the floor with your shoes.
  89. 98. Section Review p. 124 <ul><li>1. Explain why friction occurs? </li></ul><ul><li>2. Name two ways friction can be increased? </li></ul><ul><li>3. Give an example of Sliding Friction, Rolling Friction, Fluid Friction, Static Friction. </li></ul><ul><li>4. How is friction harmful and helpful when you ride a bike? </li></ul>
  90. 99. Directed Reading 5-4 <ul><li>1. Why did the astronaut in Figure 18 bounce on the moon? </li></ul><ul><li>2. The force of attraction between two objects due to their masses is the force of ______________. </li></ul><ul><li>3. Does all matter experience gravity? Explain. </li></ul><ul><li>______________________________________ </li></ul><ul><li>______________________________________ </li></ul><ul><li>4. The force that pulls you towards your pencil is called ________________ force. </li></ul>Gravity Yes because all matter has mass and gravity is a force that an object has b/c it has mass Gravitational
  91. 100. Directed Reading 5-4 <ul><li>5. Do scientists think that seeds can sense gravity? True / False </li></ul><ul><li>6. Since all objects are attracted to each other because of gravity, why can’t you see objects moving towards each other? ____________ </li></ul><ul><li>_____________________________________ </li></ul><ul><li>_____________________________________ </li></ul><ul><li>7. How are objects effected by the mass of the earth? ____________________________ </li></ul>b/c the gravity Of earth is to large for the force of gravity to overcome the force of friction.
  92. 101. Directed Reading 5-4 <ul><li>8. What did Newton find out about the moon and the falling apple? ________________ </li></ul><ul><li>___________________________________ </li></ul><ul><li>9. Newton’s law of universal gravitation describes the relationship between all the following except _____. </li></ul><ul><li>10. Which of the following are subject to the law of universal gravitation? __________ </li></ul>Both the apple and The moon are being acted upon by gravity. heat A, B, C, D
  93. 102. Directed Reading 5-4 <ul><li>11. If the distance between objects are the same the gravitational force between two feathers is greater than the gravitational force between two boiling balls. ________ </li></ul><ul><li>12. If two objects are moved_____________ each other, the gravitational force between them increases. </li></ul><ul><li>13. Why is the cat easier to pick up than the elephant? </li></ul><ul><li>___________________________________ </li></ul>False toward Cat has less mass and thus less gravitational force
  94. 103. Directed Reading 5-4 <ul><li>14. In a _____________ gravity is so great that even light can’t escape. </li></ul><ul><li>15. Why doesn’t the sun’s gravity pull you off earth? ____________________________ </li></ul><ul><li>16. The gravitational force exerted by an object depends on the _________ of the object. The measure of Earths gravitational force on an object is the objects ________________. </li></ul>Black Hole It is very far away. mass weight
  95. 104. <ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>___ </li></ul><ul><li>18. different on the moon </li></ul><ul><li>19. Expresses in (N) </li></ul><ul><li>20. Expressed in (G) </li></ul><ul><li>21. Measure of the gravitational force </li></ul><ul><li>22. Value does not change </li></ul><ul><li>23. amount of matter in an object </li></ul>W W M W M M 24. On Earth mass & weight are constant, which means that they are the same thing. True / False
  96. 105. Section Review p. 129 <ul><li>1. How does the mass of an object relate to the gravitational force the object exerts on other objects? </li></ul><ul><li>2. How does the distance between objects affect the gravity between them? </li></ul><ul><li>3. Explain why your weight would change as you orbit in a space shuttle but your mass would not. </li></ul>

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