1. Can work be done on a system if there is no motion?
A) Yes, if an outside force is provided B) Yes, since motion is only relative C) No, since a system which is not moving has no energy D) No, because of the way work is defined
2. The quantity 1/2 mv 2 is
A) the power supplied to the object by the force B) the work done on the object by the force C) the kinetic energy of the object. D) the potential energy of the object.
3. If you push twice as hard against a stationary brick wall, the amount of work you do
A) doubles. B) is cut in half C) remains constant but non-zero D) remains constant at zero
4. If the net work done on an object is positive, then the object's kinetic energy
A) increases. B) decreases C) remains the same D) is zero
5 A force of 20 N moves an object in the direction of the force. The work done when the object moves from 2.0 to 4.0 m is o A) 20 J OB) 40 J oC) 60 J D) 80 J