Question

Help?
If we want to describe work, we must have an action which causes no movement or reaction. a force and a movement in the opposite direction of the force. a force and a movement in the same direction as the force. an action which causes movement and an opposite reaction.

Answer 1

Hi,
As can be seen from the definition of work itself, work is done when a force causes displacement ( or movement in 1-D motion.) The movement can occur both ways opposite or towards the force ( negative and positive work respectively.) Clearly, option D is correct.

Also each force must have an equal and opposite reaction, hence again D is correct.

Mathematically,
W = FScosx
As long as x is not 90 work is done.

Answer 2

@Justanotherguy Thank you!

Answer 3

Pleasure.