Petra pushes a crate across a rough floor.A frictional force of 28.0 N acts to oppose the motion of the crate,and Petra pushes with a horizontal force of 36.4 N.If the net work Petra does is 94.5 J,through what distance did she push the crate?
A)11.3 m
B)3.38 m
C)2.60 m
D)2 650 m
E)3 440 m

Question

Quizplus · Accepted Answer

The net work done on the crate is equal to the work done by Petra minus the work done by friction. So, the net work done is:$$W_{net} = W_{Petra} - W_{friction}$$$$94.5 J = 36.4 N * d - 28.0 N * d$$$$94.5 J = 8.4 N * d$$$$d = 11.3 m$$

Petra Pushes a Crate Across a Rough Floor