Upcoming SlideShare
×

# Speed Intro

1,532 views

Published on

0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
1,532
On SlideShare
0
From Embeds
0
Number of Embeds
706
Actions
Shares
0
13
0
Likes
0
Embeds 0
No embeds

No notes for slide

### Speed Intro

1. 1. MOTION • We now know that unbalanced forces can change motion
2. 2. Recognizing Motion Textbook pg 17-18 • When is an object in motion? • Are you or your book moving – Compared to the floor? – Compared to the sun? • What is a reference point? • What do we assume about a reference point? • For the bus example, why do you think you are moving backward?
3. 3. Recognizing Motion ANSWERS Textbook pg 17-18 • When is an object in motion? • When it’s distance from another object is changing • Are you or your book moving? – Compared to the floor? NO – Compared to the sun? YES • What is a reference point? • A place or object used for comparison • What do we assume about a reference point? • It is stationary
4. 4. Recognizing Motion ANSWERS Textbook pg 17-18 • For the bus example, why do you think you are moving backward? –Your reference point (the other bus) wasn’t stationary You  Reference  point
5. 5. What’s a Frame of Reference?
6. 6. BACKGROUND OR OBJECT USED FOR COMPARISON
7. 7. NOW WE ARE GOING TO LOOK AT WAYS TO DESCRIBE AND MEASURE MOTION SPEED
8. 8. HOW DO WE DESCRIBE SPEED? HOW FAST SOMETHING GOES
9. 9. How do we CALCULATE SPEED? • How we describe the speed of a CAR: – Miles per hour (MPH) OR – Kilometers per hour (km/h) • What does the miles or kilometers measure? – They are units for distance • What does the hour measure? – It is a unit for time • What does the “per” or “/” mean in math? – division
10. 10. SPEED =RATE that an object moves Distance (D) Rate (speed) = Time (T)
11. 11. DISTANCE Length between two places Distance = rate (speed) x time D= RT “Dirt”
12. 12. TIME = d r (speed)T
13. 13. STEPS IN PROBLEM SOLVING  STEP 1. Write the formula  STEP 2. Substitute given numbers and units  STEP 3. Solve for the unknown.
14. 14. SAMPLE PROBLEM: At what speed did a plane fly if it traveled 1760 meters in 8 seconds?
15. 15. SOLUTION Step 1. Question asked “What speed” so use: Rate (Speed) = Distance/Time
16. 16. SOLUTION Step 2. substitute distance = 1760 meters substitute time = 8 seconds Speed = 1760 meters/ 8 seconds
17. 17. SOLUTION Step 3. Do the math to get your answer Speed = 220 meters/second (m/sec)
18. 18. SAMPLE PROBLEMS: 1. A car travels 240 kilometers in 3 hours. What is the speed of the car during that time? ANSWER: S= d/t S= 240 km/3 hr 80 KM/HR
19. 19. The speed of a cruise ship is 50 km/hr. How far will the ship travel in 14 hours? Answer: D = ST 700 km