A 10.0 g bullet is fired into a stationary 5.00 kg block of wood. The bullet lodges inside the block. The speed of the block plus bullet system immediately after the collision is measured at 0.600 m/s. What was the original speed of the bullet?
Dec 20­6:35 AM
1
A 0.0420 kg hollow racquetball with an initial speed of 12.0 m/s collides with a backboard and rebounds with a speed of 6.0 m/s.
a.) Calculate the TOTAL impulse on the ball.
b.) If the contact time lasts for 0.040 s, calculate the average force on the ball
Dec 20­6:39 AM
2
A rope is used to pull a metal box a distance of 15 meters across the floor. The rope is held at a 46 degree angle to the horizontal. A force of 628N is applied to the rope. How much work does the force on the rope do?
Dec 20­6:39 AM
3
A 7.0kg bowling ball moves at 3.0 m/s. How fast must a 2.45g ping pong ball move so that the two balls have the same kinetic energy?
Dec 20­6:40 AM
4
At 9.0 seconds after takeoff, a 250kg rocket attains a vertical velocity of 120 m/s.
a.) What is the impulse given to the rocket?
b.) What is the average force that acted on the rocket?
c.) Find the altitude of the rocket. Dec 20­6:40 AM
5
A pitcher throws a 0.15kg baseball so that it crosses home plate horizontally with a speed of 20m/s. The ball is hit straight back at the pitcher with a final speed of 22m/s.
a.) What is the impulse delivered to the ball?
b.) Find the average force exerted by the bat on the ball if the two are in contact for 2.0X10­3 seconds.
A railroad car of mass 2.0X104kg moving at 3.0m/s collides and couples with two coupled railroad cars, each with the same mass as the single car and moving in the same direction at 1.2m/s. 3.0 m/s 1.2 m/s
all 3 initially moving
a.) What is the speed of the three coupled cars after the collision?
b.) How much kinetic energy is lost in the collision?
Dec 20­6:47 AM
6
A rifle with a weight of 30N fires a 5.0g bullet with a speed of 300m/s.
Find the recoil speed of the rifle
The force versus time graph acts on a 1.5kg object. Using info from the graph find:
a.) the impulse of the force
b.) The final velocity of the object if it were initially at rest
c.) The final velocity of the object if is was initially moving along the x­axis with a velocity of ­2.0m/s
Dec 20­6:47 AM
7