Physics homework sheet 2

Please Provide All solutions for the answer to these problems. I have the answer I am looking at how you came to this answer.

1. A 475 gram ball is traveling horizontally at 12.0 m/s to the left when it is suddenly struck horizontally by a bat, causing it to reverse direction and initially travel at 8.50 m/s to the right. If the bat produced an average force of 1275 N on the ball, for how long (in ms) was it in contact with the ball?

2. A girl of mass 54 kg throws a ball of mass 0.9 kg against a wall. The ball strikes the wall horizontally with a speed of 23 m/s, and it bounces back with this same speed. The ball is in contact with the wall 0.05 s. What is the average force exerted on the wall by the ball?

Answer 830 N

3. A 0.24 kg blob of clay is thrown at a wall with an initial velocity of 18 m/s. If the clay comes to a stop in 91 ms, what is the average force experienced by the clay?

4. A 312 kg car moving at 17.7 m/s hits from behind another car moving at 13.2 m/s in the same direction. If the second car has a mass of 347 kg and a new speed of 15.5 m/s, what is the velocity of the first car after the collision?

5. An object initially at rest explodes in two fragments of masses 4.6 kg and 7.8 kg that move in diametrically opposite directions. If the speed of the first fragment is 6.2 m/s, find the internal energy of the explosion.

6. A 0.140 kg baseball is thrown with a velocity of 24.1 m/s. It is struck with an average force of 5000.0 N, which results in a velocity of 37.0 m/s in the opposite direction. How long were the bat and ball in contact?

7. Two carts, one twice as heavy as the other, are at rest on a horizontal frictionless track. A person pushes each cart with the same force for 4.00s .

If the kinetic energy of the lighter cart after the push is K, the kinetic energy of the heavier cart is 1/2K Why .

8. A small car collides head-on with a large SUV.

Which of the following statements concerning this collision are correct?

A. Both vehicles are acted upon by the same average force during the collision. B. The small car is acted upon by a greater average force than the SUV. C. The small car undergoes a greater change in momentum than the SUV. D. Both vehicles undergo the same change in momentum.

9. A 1200 kg cannon fires a 100.0 kg cannonball at 36 m/s. What is the recoil velocity of the cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.

10. Cart A, of mass 3.00kg , approaches and collides with cart B, which has a mass of 7.00kg and is initially at rest. When the springs have reached their maximum compression,

11. Two lumps of clay having equal masses and speeds, but traveling in opposite directions, collide and stick together.

Which of the following statements about this system of lumps must be true?

A. The momentum of the system is conserved during the collision. B. The kinetic energy of the system is conserved during the collision. C. The two masses lose all their kinetic energy during the collision. D. The velocity of the center of mass of the system is the same after the collision as it was before the collision. 12. a bullet of mass 0.01 kg moving horizontally strikes a block of wood of mass 1.5 kg which is suspended as a pendulum. The bullet lodges in the wood, and together they swing upward a distance of 0.40 m. What was the velocity of the bullet just before it struck the wooden block? The length of the string is 2 meters 13. A block of mass m = 7.6 kg, moving on a frictionless surface with a speed vi = 7.4 m/s, makes a perfectly elastic collision with a block of mass M at rest. After the collision, the 7.6 kg block recoils with a speed of vf = 0.5 m/s. In the figure, the speed of the block of mass M after the collision is closest to 14. A steady horizontal force lasting for 2.10 s gives a 1.25 kg object an acceleration of 3.20 m/s2 on a frictionless table. What impulse does this force give to the object? 15. A block of mass m = 40 kg has a speed V and is behind a block of mass M = 71 kg that has a speed of 0.5 m/s. The surface is frictionless. The blocks collide and couple. After the collision, the blocks have a common speed of 0.9 m/s. In the figure, the loss of kinetic energy of the blocks due to the collision is closest to: 16. A block of mass m = 8.4 kg, moving on frictionless surface with a speed vi = 4.6 m/s, makes a perfectly elastic collision with a block of mass M at rest. After the collision, the 8.4 kg block recoils with a speed of vf = 0.7 m/s. In the figure, the mass M is closest to: 17. Three objects are moving along a straight line as shown in the figure. Taking the positive direction to be to the right, what is the total momentum of this system? 18. A 1200 kg car moving at 16.8 m/s collides with a stationary car of mass 1500 kg. If the two vehicles lock together, what is their combined velocity immediately after the collision? 19. A golf ball of mass 0.050 kg is at rest on the tee and has a velocity of 102 m/s immediately after being struck. If the club and ball were in contact for 0.76 ms, what is the average force exerted on the ball?