3. A 5.0-g bullet travelling at 625 m/s strikes a block, causing it to move back by 6.0 cm before stopping. Assume that the stopping force is constant.

9. A 58.4 gram tennis ball is thrown down at the ground. Right before it strikes the floor, its speed is 28.8 m/s. The ball then bounces back off the floor, upwards at 20.5 m/s. If the ball is in contact with the floor for 64.4 ms, calculate the average force on the ball (magnitude and direction). Assume the convention that upward is positive. a. 7.53 N; upward b. 44.7 N; upward c. 44.7 N; downward d. 7.53 N; downward e. 2.88 N; upward

lower a crate of mass ?1=5.00 kgm1=5.00 kg to the bottom of a steep ravine of height ?=25.0 mH=25.0 m. The crewman of mass ?2=55.6 kgm2=55.6 kg is walking while holding the rope, being careful to lower the crate at a constant speed of ?0=1.50 m/sv0=1.50 m/s. Unfortunately, when the crate reaches a point ℎ=13.9 mh=13.9 m above the ground, the crewman steps on a slick patch of ice and slips. The crate immediately accelerates toward the ground, dragging the hapless crewman across the ice and toward the edge of the cliff. Assuming the ice is perfectly slick, so that there is no friction between the crewman and the ice once he slips and falls down, at what speed ?1v1 will the crate hit the ground? Assume also that the rope is long enough to allow the crate to hit the ground before the crewman slides over the side of the cliff, and that the pulley is frictionless. ?1

A 0.170kg hockey puck is initially moving at 21.2m/s[W] along the ice. The coefficient of kinetic friction for the puck and the ice is 0.005. what is the speed of the puck after traveling 58.5m

3. An urban myth states that a penny dropped from the top of the Empire State Building (1440 ft tall) in NYC could be lethal. Ignore air friction and find the final velocity of the penny.

18. Two trolleys, of mass 1.2 kg and 4.8 kg. are at rest with a compressed spring between them, held that way by a string tied around both. When the string is cut, the trolleys spring apart. If the force constant of the spring is 2400 N/m, by how much must it have been compressed in order that the 4.8 kg cart move off at 2.0 m/s?

1. A 2.50-kilogram mud ball drops from rest at a height of 13.0 m. If the impact between the ball and the ground lasts 0.51 s, what is the magnitude of the average force exerted by the ball on the ground? f60 f60 sst ssfo ssf60

A1500 kg car was moving +31 (E) in the exit lane, but 7.0 s later only +10 "/ (E) at the exit ramp. a) what was the car's average acceleration during that interval? +20.5 m/ s² (E) +21 m/s (E) -21 m/s (W) +3 m/g² (E) +5.86 "/g² (E) -3 "/s² (W) m

Male bighorn sheep (120 kg ) engage in head-butting contests to establish dominance. High-speed photography has shown that the impact speed is typically 6.0 m/s and that the collision, which brings both rams to a halt, lasts approximately 0.25 s . Suppose the collision force increases linearly with time until it reaches a maximum Fmax , then decreases linearly to zero at t = 0.25 s.  What is Fmax?

3. A0.03-lb bullet traveling at 1300 ft/s strikes the 10-lb wooden block and exits the other side at 50 ft/s as shown. Determine the speed of the block just after the bullet exits the block, and also determine how far the block slides before it stops. The coefficient of friction between the block and the surface is u = 0.5. 50 ft/s 13 4 1300 ft/s 12