Question

A force act on an object moves at right angle to the direction of the force. What is the work done on the object?

Answer 1

since the force is acting at right angle to the direction of the force.
therefore, work done = force . displacement
                                   =force x displacement x cos90 (since f.d = fdcos90)
                                   = 0    (since cos 90= 0)

Answer 2

Work Done is 0
W = Fdcos(90)