newtons laws of motion -physics

2,479 views
2,168 views

Published on

nice presentations with good material nice animation and based on easy concept of power point making.

Published in: Education, Technology
0 Comments
7 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
2,479
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
329
Comments
0
Likes
7
Embeds 0
No embeds

No notes for slide

newtons laws of motion -physics

  1. 1. Newton's Laws of Motion
  2. 2. Index Objectives Force Newton’s first law Inertia Newton’s second law Newton’s third law Evaluation
  3. 3. Objectives Understand the ideas of motion and force Describe Newton's three laws of motion Understand the idea of inertia Test Newton's three laws of motion in their class room
  4. 4. Force Push can change the state of the object from one place to another.
  5. 5. Pull can change the state of the object from one place to other. Force (contd..)
  6. 6. Stretch and squeeze can change the state of the state of the object from one place to other. Force (contd..)
  7. 7. Force (contd..) Twist can change the state of the object from one place to other.
  8. 8. WHEN THERE IS A PULL ... WHEN THERE IS A PUSH... WHEN THERE IS A STRETCH... WHEN THERE IS A SQUEEZE ... WHEN THERE IS A TWIST... We experiences some effect called forces. We can’t see forces but we can see the effect of a force. Force (contd..)
  9. 9. The ball remains in its state of rest till an external force is acting on it. Newton’s first law
  10. 10. When an external force (push) is acting on a ball (object) at rest it changes its state (moves over the steps ). Newton’s first law (contd..) Push the ball
  11. 11. object in motion tends to stay in motion Newton’s first law (contd..)
  12. 12. When external force (Push of the rabbit) acting on the object (ball) which is in motion the object changes its position. Newton’s first law (contd..) Push the ball
  13. 13. From the above observation... Newton’s first law (contd..) An object remains in its state of rest if no external force is acting on it. An object remains in its state of motion if no external force is acting on it. An object changes its state of rest or uniform motion if some external force acting on it.
  14. 14. An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless an external force is acting on it. The above three statement can be written as a single statement which is the Newton’s first law In other words Every body continuous in its state of rest or in uniform motion Unless an external force is acting on it. Newton’s first law (contd..)
  15. 15. When the car hits the wall…… The moving car stopped when a force (from the wall) is acting on it. Driver who is moving along with the car could not able to stop himself when the car stopped. Driver has inability to change his position by himself at that instant. Inertia
  16. 16. When the truck hits the car…… The moving truck stopped when a force (from the car) is acting on it. Ladder which is moving along with the truck could not able to stop itself when the truck stopped. Ladder has inability to change its position by itself at that instant Inertia (contd..)
  17. 17. It is the natural tendency of objects to resist changes in their state of motion. This tendency to resist changes in their state of motion is described as inertia. This can be said in a single statement Inability of an object to change its position by itself is called Inertia. Inertia (contd..)
  18. 18. Inertia (contd..) Try the following activity to demonstrate inertia Why will the coin drop into the glass when a force accelerates the card? Why does the downward motion and sudden stop of the hammer tighten the hammer head?
  19. 19. It is too hard It is very easy Smaller force is needed to move smaller mass Larger force is needed to move larger mass Newton’s second law
  20. 20. 10 n 30 n Smaller force give smaller acceleration Larger force give Larger acceleration Newton’s second law (contd..)
  21. 21. If a bowling ball and a soccer ball were both dropped at the same time from the roof of a tall building, which would hit the ground with a greater force? Acceleration due to gravity accelerates downwards all objects at the same rate. Therefore the difference in forces would be caused by the different masses of the balls. The mass of the bowling ball is greater than the mass of the soccer ball. The bowling ball experience greater force than soccer ball. So, bowling ball hit the ground first. Newton’s second law (contd..)
  22. 22. Smaller force (F) is needed to move smaller mass (m) Larger force (F) is needed to move larger mass (m) So, Force is directly proportional to mass F α m Smaller force (F) give smaller acceleration (a). Larger force (F) give smaller acceleration (a). So, Force is directly proportional to acceleration (a). F α a Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). Newton’s second law states that the net force on an object is proportional to the mass and the acceleration that the object undergoes. F = ma Newton’s second law (contd..)
  23. 23. Look at the flying motion of birds. A bird flies by the use of its wings. The wings of a bird push air downwards. The air reacts by pushing the bird upwards. The direction of the force on the air (downwards) is opposite to the direction of the force on the bird (upwards). These two forces are equal and opposite. a c t i o n r e a c t i o n Newton’s third law
  24. 24. Look at the flying motion of rocket. Hot gases are pushed out from the bottom of the rocket as the rocket is thrust upward. The force of the gases pushing against the surface of the earth is equal and opposite to the force with which the rocket moves upward. These two forces are equal and opposite. Newton’s third law (contd..)
  25. 25. Look at the recoil effect of the gun. When we trigger the gun, the gun pushes the bullet forwards and the bullet pushes the gun backwards. The bullet has a greater acceleration due to the fact that it has a smaller mass. (Newton's second law) These two forces are equal and opposite. action reaction Trigger the gun Newton’s third law (contd..)
  26. 26. Try it 1. Blow up a balloon. 2. Hold the opening downward and release the balloon. 3. Repeat this several times, and observe what happens. 4. Now describe what happened using Newton's third law of motion. "For every action, there is an equal and opposite reaction." There fore the action and reaction forces can be represented in a single statement that we called as Newton’s second law. Newton’s third law (contd..)
  27. 27. Evaluation Click true or false 1. Force is the effect of push or pull 2. A ball which is in motion can come to rest without any external force. 3. Working principle of rocket can be explained by using Newton’s second law. 4. Inability of an object to change its position by itself is called Inertia. 5. The below diagram can be explained by Newton’s third law. True False True False True False True False True False
  28. 28. Very Good Back to the questions
  29. 29. Try again Back to the questions

×