1. Hoai Nguyen, a Physics 2A student, drop a soccer ball from the roof of the new science building. The ball strikes the ground in 3.30 s later. You may ignore air resistance, so the ball is in free fall. How tall, in meters, is the building?

2. How fast was the ball moving right before hitting the floor?

3. Thu Tran, another Physics 2A student, grabs the ball and kicks it straight up to Hoai Nguyen, who is still up on the building rooftop. Assuming that the ball is kicked at 0.50 m above the ground and it goes on a vertical path, what is the minimum velocity required for the ball to make it to the building rooftop? Ignore air resistance. (Hint: the ball will pass the rooftop level with a higher speed...)

Determine the amount of work done when a crane lifts a 100-n block form 2m above the ground to 6m above the ground

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

A3030 cmcm wrench is used to loosen a bolt with a force applied 0.30.3 mm from the bolt. it takes 6060 nn to loosen the bolt when the force is applied perpendicular to the wrench. how much force would it take if the force was applied at a 3030 degree angle from perpendicular? a 3030 cmcm wrench is used to loosen a bolt with a force applied 0.30.3 mm from the bolt. it takes 6060 nn to loosen the bolt when the force is applied perpendicular to the wrench. how much force would it take if the force was applied at a 3030 degree angle from perpendicular?