HELP! Impulse-Momentum Problems

Wellgrin SG

1. A bullet with a mass of 0.0050kg and moving with a speed of 400 m/s penetrates a distance of 0.08m into a wooden block firmly attached to the earth. Assume that the force that stops it is constant.

Compute for:
a) The acceleration of the bullet
b) The accelerating force
c) The time of the acceleration
d) The impulse of the force

2. A baseball has a mass of 0.200kg.
a) If the velocity of a pitched ball has a magnitude of 35m/s in the opposite direction, find the change in momentum of the ball and the impulse applied to it by the bat.
b) If the ball remains in contact with the bat for 2.0x10^-3 sec, find the average force applied by the bat.

3.) A ball with a mass of 0.40kg is thrown against a brick wall. It hits the wall moving horizontally to the left at 30m/s and it rebounds horizontally to the right at 20 m/s. Find the impulse of the force exerted on the ball by the wall. If the during the impact for 0.010sec, find the average force on the ball during the impact.

Audioboxing SG

1) since the object is fully decelerated constantly,

s = 1/2 at² = 1/2 vt

solve for t. then find acceleration using a=v/t. Then find the force using F=ma. Since the object comes to a stop, it loses all it's momentum. Hence the impulse of the force is the initial momentum of the object.

2) don't understand the question, don't think there is a way to do it in the first place as it depends on the initial velocity of the baseball...maybe some other forumers can help.

3) find the change in momentum, that is the impulse. Clue: the difference between +5 and -5 is 10. Find the average force by using F = I/t.

8008s SG

O.O