Choose the best answer. A car traveling at constant speed has a net work of zero done on it. (a) True (b) False (c) The answer depends on the motion.

Ex(N) 80 50 25 X(m) 10 25 40 50 58 1) Work by a force, drawn on a graph, determine: a) The total work done by the force. b) Work at (10sx<40) m?

A worker pushing a 35.0-kg wooden crate at a constant speed for 13.6 m along a wood floor does 400 J of work by applying a constant horizontal force of magnitude F0 on the crate. (a) Determine the value of F0. ____N (b) If the worker now applies a force greater than F0, describe the subsequent motion of the crate. (c) Describe what would happen to the crate if the applied force is less than F0.

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?