The three ropes shown in the bird’s-eye view of FIGURE EX9.19 are used to drag a crate 3.0 m across the floor. How much work is done by each of the three forces?

Abigail is sliding down a slippery-wet grassy hill, speeding up, before landing in a pile of leaves. Rank the following amounts of work from the most negative to the most positive:   Hint: Think about the angle between a given force and the direction that she's travelling. 1. Work performed on Abigail by friction forces while she was sliding, slowing her down just a little bit.   2. Work performed by the drag force of the leaf pile against Abigail, bringing her to a stop from a dangerously high speed.   3. Work performed by the normal force of the hill pushing on Abigail along the hill, while she was sliding.   4. Work performed on Abigail by gravity, from beginning to end.

A middle school kid is pushing a lawn mower with 46 N of force at an angle 31 degrees below the horizontal and walks for a total 350 m of distance to finish mowing a neighbor's lawn. How many Joules of work does the kid do to the lawn mower? Hint: above and below horizontal is no difference in this question.

A 1.6 kg book is lying on a 0.79 m -high table. You pick it up and place it on a bookshelf 2.0 m above the floor.  During this process, how much work does gravity do on the book?