If you push a crate horizontally with 100 n across a 10 m factory floor and the friction between the crate and the floor is a steady 70 n, how much kinetic energy does the crate gain?

300 J

Explanation:

First of all, we need to calculate the net force acting on the crate, which is given by:

where

F = 100 N is the horizontal push

is the force of friction

Substituting,

Now we can calculate the net work done on the crate:

where

d = 10 m is the displacement

Substituting,

According to the work-energy theorem, the kinetic energy gained by the crate is equal to the work done on it: therefore, the answer is 300 J.

0.71m/s

Explanation:

Formula: Speed = Distance/time

Speed = 100m/140s

Speed = 100/140 / 20/20

Speed = 5/7 or 0.71m/s