A 73-kg boy is surfing and catches a wave which gives him an initial speed of 1.6 m/s. He then drops through a height of 1.55 m, and ends with a speed of 8.5 m/s. How much nonconservative work (in kJ) was done on the boy?

If, in actuality, a 750-kg car with an initial speed of 116 km/h is observed to coast up a hill and stops at a height 24.5 m above its starting point, how much thermal energy was generated by friction in J?

A 77-kg object starts with a speed of 1.3 m/s, drops through a height of 1.65 m, and ends with a speed of 8.2 m/s.  How much non-conservative work was done on the object?

A motorcyclist runs out of gas on a level road 250 m from the gas station. She pushes the 220-kg motorcycle with a constant force of 150 N. How much work does she do?   For the motorcycle of the previous problem, if it was moving with a kinetic energy equal to the work done on it, how fast would it move?

A basketball playet makes a jump shot. The 0.600 kg ball is released at a height of 2.08m above the floor with a speeed of 7.31 m/s. The ball goes through the net 3.10 m above the floor at a speed of 4.03 m/s. What is the work done by the ball by air resistance, a nonconservative force  ?

Starting from rest, a horse pulls a 241-kg cart for a distance of 1.50 km. It reaches a speed of 0.380 m/s by the time it has walked 50.0 m and then walks at constant speed. The frictional force on the rolling cart is a constant 291 N. Each gram of oats the horse eats releases 9.00 kJ of energy; 10.0% of this energy can go into the work the horse must do to pull the cart. How many grams of oats must the horse eat to pull the cart?

A 3 kg block is sliding across a horizontal surface.  The initial speed of the block is 4 m/s, but because of friction the block’s speed will decrease at a constant rate (i.e., constant acceleration) until the block finally comes to a stop after sliding 8 m.  What is the average power (in W) supplied by friction as the block slows to a stop?

An object is displaced by 0.5m against a force of friction at 2N. What is the work done on the object by the friction? -6J 1J -1J 4J

20- A 65-kg boy is surfing and catches a wave which gives him an initial speed of 1.6 m/s. He then drops through a height of 1.58 m, and ends with a speed of 8.5 m/s. How much nonconservative work (in kJ) was done on the boy?

A crate of mass 11.0 kg is pulled up a rough incline with an initial speed of 1.48 m/s. The pulling force is 92 N parallel to the incline, which makes an angle of 20.6° with the horizontal. The coefficient of kinetic friction is 0.400, and the crate is pulled 5.06 m. (a) How much work is done by the gravitational force on the crate? (b) Determine the increase in internal energy of the crate-incline system owing to friction. (c) How much work is done by the 92-N force on the crate? (d) What is the change in kinetic energy of the crate? (e) What is the speed of the crate after being pulled 5.06 m? m/s