1. A jeep with mass of 2000 kg is going 18 m/s at the bottom of a hill that is 50.0m high. When it reaches the top, it is travelling at 10m/s. (a) what is the total work done by all forces (the jeep engine, the mud, gravity, etc) as it ascends the hill? (b) What is the minimum work required by engine of the jeep if only the engine and gravity are doing work (if there is no friction, forces from mud, etc)?

A factory worker pushes a 30.0 kg crate a distance of 3.7 m along a level floor at constant velocity by pushing downward at an angle of 30∘ below the horizontal. The coefficient of kinetic friction between the crate and floor is 0.25. How much work is done on the crate by this force when the crate is pushed a distance of 3.7 m? How much work is done by the normal force? How much work is done by gravity? What is the total work done on the crate?

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A man starts at ground level and carries a 20 kg box up a flight of stairs to a height of 3.6 m. He then carries the box down an adjacent flight of stairs back to ground level and ends up 10 m away from where he started. What is the total amount of work the man has done? Explain

A cheerleader lifts his 68 kg partner straight up off the ground a distance of 0.72 m before releasing her. Assume the partner’s velocity is zero at the beginning and the end of the lift. The acceleration of gravity is 9.8 m/s2 . If he does this 22 times, how much work has he done? Answer in units of J.

26. A 2000 kg car with speed 12.0 m/s hits a tree. The tree does not move or break and the front of the car is smashed inward 50.0 cm. Ignore friction. (a) Determine the work done on the car by the tree. (b) Determine the amount of force involved.

A car with the mass m=1600kg coasts down an incline from an initial height of h=7m with an initial speed v0=15m/s. When it reaches the bottom of the incline its speed is 20m/s. How much work did friction do on the car? This is the full question. No acceleration given. Assistance please.

5. A person pulls an object of mass 40 kg as far as 20 m above a flat floor at a constant speed. The force used is directed 370 upwards horizontally. The coefficient of kinetic friction of the object with the floor is 0.20. Determine the work by the person, the work by the frictional force, and the total work on the object.

During terrible weather at a ski-flying world championship, a ski jumper tried to adjust for bad conditions midway down the ramp but completely lost control and tumbled wildly off the side at its bottom into a scattering crowd. The 73-kg jumper left the ramp about 45 m lower than his starting position. After hitting the ground, the jumper crashed wildly and descended down the hill another 20 vertical meters before coming to rest. Here, friction cannot be ignored. Calculate the total work done on the ski jumper to bring him to rest. Round the final answer to the nearest whole number.

4. A 6.00-kg watermelon is dropped from rest from the roof of a 30.0-m-tall building and feels no appreciable air resistance. (a) Calculate the work done by gravity on the watermelon during its displacement from the roof to the ground. (b) Just before it strikes the ground, what is the watermelon's (i) kinetic energy and (ii) speed? (c) Which of the answers in parts (a) and (b) would be different if there were appreciable air resistance?