Question

#1. How much work is done when you push a crate horizontally with 80N across a 9.0-m factory floor? #2. If the force of friction on the crate is a steady 70 N, find the KE gained by the crate. #3. Find the energy turned into heat.

Answer 1

1. Work is termed as the force that moves an object at a certain distance. It equal to force times distance. W=Fd = 80N*9m = 720 N.m or 720 J
2. Assume that no energy is lost in the process. KE (kinetic energy)= (80 N - 70N)* 9m= 90 N.m or J.
3. The energy that turned to heat is Q (heat) = W + KE + PE (potential energy). The potential energy is zero and substituting the values for W and KE. Q(heat) = 720J - 90J = 630J

Answer 2

#1. 720 Nm
Work = force x distance
Work = 80N x 9m = 720 Nm
#2. 90J
Assume no energy lost in the process,
Kinectic energy=(80N - 70N) x 9m = 90J
#3. 630J
Heat energy = work - kinetic energy
Heat energy = 720J - 90J = 630J