if a 30.0kg crate is pushed across a horizontal surface at a constant velocity

Question

a. the force acting forward is greater than the force acting backward
b. the net force has a value directed forward
c. the net force is zero
d. the forces acting on the crate are "unbalanced"
e. there may be no force acting backward

Answer 1

c. the net force is zero. Since the crate is moving at a constant velocity, the forces acting on it must be balanced, meaning the forward force pushing it is equal and opposite to the backward force of friction.