Question

No work is accomplished in which of the following situations?

A. A refrigerator on rollers is pushed across a level floor at a constant velocity.
B. A girl pulls up on a window to open it, but it won't move.
C. A boy lifts a 4.0-newton box to a height of 1.0 meter.
D. all of the above

Answer 1

No work is accomplished when a girl pulls up on a window to open it, but it won't move, as work requires force to cause displacement, which doesn't occur in this situation.

Step-by-step explanation:

No work is accomplished in the situation where a girl pulls up on a window to open it, but it won't move. In physics, work is defined as force applied over a distance. In this scenario, despite the force exerted by the girl, there is no displacement of the window; therefore, work done is zero. This corresponds to situation B in the options provided. On the contrary, pushing a refrigerator at a constant velocity (situation A) involves work against friction (even if the floor is level), and lifting a box (situation C) involves work against gravity. Both A and C involve displacement with force applied and, hence, work is done.