Give TWO conditions in which a force is exerted on an object without doing any work on the object.

1)There is no movement. You stand still, gravity pulls you down but the ground prevents you from moving so gravity does no work on you.

2)There is movement but it is not in the direction of the force (at all). The most common example of this is a catr travellling along a horizontal road. gravity neither helps nor hinders the car. It does no work on the car because the car does not move in the direction of the graviational force. Notice that once the road is inclined, the car partly moves in the direction of gravity and it has some effect. It reduces your kinetic energy if you were going uphill and increaes it when coming down.

ANY time a force is exerted but the object is not displaced in a direction parallel to the force, work is not done. Force of tension on a ball rotating on the end of a string. Normal force and gravitational force on an object at rest or moving across a level floor.

Explanation:

to be honest as much as i would love to answer this. i feel as if something's missing. just saying.