Calculate the work done on a 1500-kg elevator car by its cable to lift it 50.0 m up at constant speed, assuming friction averages 100 N.

You are biking along a country road whenyou reach the base of a bridge travelling at 5.00 m/s. At the top of the bridge you have climbed a vertical distance of 5.20 m and have slowed to 1.50 m/s. Ignore any work done by friction or any inefficiency in the bike or your legs. (a) What is the total work done on you and your bike in going from the base of the bridge to its topif the total mass of you and your bike is 80.0 kg? (b)How much work have you done with the force you apply to the pedals?

Calculate the work done (in J) on a 1550 kg elevator car by its cable to lift it 37.5 m at a constant speed, assuming friction averages 115 N.   What is the total work done (in J) on the lift?

A  6.8kg block is being pushed up a frictionless plane inclined at  35o to the horizontal. (a) Calculate the work done by the normal force (b) Calculate the work done by the gravitational force as the block moves  3.6m along an axis parallel to the inclined plane.

A 7.80-g bullet moving at 560 m/s penetrates a tree trunk to a depth of 4.80 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.

A 7.80-g bullet moving at 640 m/s penetrates a tree trunk to a depth of 6.10 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.

(a) The Eskimo a 50.0-kg sled over level ground with a force of 1.80  102 N exerted horizontally, moving it a distance of 6.30 m over new terrain. If the net work done on the sled is 1.90  102 J find the coefficient of kinetic friction.(b) Repeat the exercise with the same data, finding the coefficient of kinetic friction, but assume the applied force is upwards at a 35.0° angle with the horizontal.

An elevator having a mass of 585 kg is raised a distance of 32 m. Determine the work done, neglecting frictional effects and the work required for acceleration.

A warehouse worker pushes a crate of mass 24kg up a ramp. Assume that he pushes 4.0m from rest in exactly 8.0 seconds. Assume further that the box is moving up the incline at a constant speed. If the effective coefficient of friction is 0.25, determine the average force 0 = 30.0° exerted onto the box. What will be the power? Answer: assuming acceleration is a constant, As = (v+v,)At v, =1.0 m avgAs =– 2 m(v; -vi )=F. W. = 3.0N, P= At 12J =1.5W 8s net avg Source: modified from Nelson, Physics 12, 2009, p. 170, Question #5

A 2,200-kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 4.60 m before coming into contact with the top of the beam, and it drives the beam 15.0 cm farther into the ground as it comes to rest. Using energy considerations, calculate the average force the beam exerts on the pile driver while the pile driver is brought to rest. magnitude X N direction |upward