a stack of books has a mass of 40 kg. A woman lifts the books from the floor a distance of 2 m. How much work is done? The women carries the books 15 m to her car. How much work is done. The women lowers the books 1.5 m into her car trunk. How much work is done?

A spring and block are in the arrangement of the figure. When the block is pulled out to x = +5.0 cm, we must apply a force of magnitude 370 N to hold it there. We pull the block to x = 14.0 cm and then release it. How much work does the spring do on the block when the block moves from x₁ = +5.0 cm to (a) x = +4.0 cm, (b) x = -4.0 cm, (c) x= -5.0 cm, and (d) x = -10.0 cm? (a) Number i (b) Number i (c) Number i (d) Number i x=0 F = 0 00000000 x positive F, negative F moon Units Units Units (a) Units (b) d Block attached to spring x negative F, positive x x x

A sled of mass 70 kg starts from rest and slides down a 10° incline 80 m long. It then travels for 20 m horizontally before starting back up an 8° incline. It travels 80 m along this incline before coming to rest. What is the magnitude of the net work done on the sled by friction?

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?