Question

A force acting on an object does NO work if:

a
the object accelerates
b
the force is greater than the force of friction
c
the force is not in the direction of the object's motion
d
a machine is used to move the object

Answer 1

c) the force is not in the direction of the object's motion. In order for work to be done on an object by a force, the force must be in the same direction as the object's displacement.