A 390 kg crate hangs from the end of a rope of length L =14.0m. You push horizontally on the crate with a varying force F to move it a horizontal distance d =3.90 m to the side. Find the work your force F does on the crate in Joules.

You drop a 2.50 kg book to a friend who stands on the ground at distance D-13.0 m below. If your friend's outstretched hands are at distance d-1.60 m above the ground (see the figure), (a) how much work W, does the gravitational force do on the book as it drops to her hands? (b) What is the change AU in the gravitational potential energy of the book-Earth system during the drop? If the gravitational potential energy U of that system is taken to be zero at ground level, what is U (c) when the book is released and (d) when it reaches her hands? Now take U to be 100 J at ground level and again find (e) W. (f) AU, (g) U at the release point, and (h) U at her hands. 10000 El

A 68.3-kg skier coasts up a snow-covered hill that makes an angle of 25.5 ° with the horizontal. The initial speed of the skier is 9.77 m/s. After coasting a distance of 1.45 m up the slope, the speed of the skier is 3.60 m/s. (a) Find the work done by the kinetic frictional force that acts on the skis. (b) What is the magnitude of the kinetic frictional force? (a) Number i (b) Number i Units Units 0

A 50 N force is applied at an angle to the side of a box causing it to slide across a floor. The total work done to move the box 10m is 150 J (joules).  A) what is the angle at which the force was applied?  B) if the box has a weight of 735 N, what is the mass of the box?