Question

1. which of the following objects has no work done on it?

a wall that is being pushed on by a person
a wagon pulled down a sidewalk
a ball that is pushed down a hill
a baseball that is lifted off the floor

Explanation:

In physics, work is defined as $W = F \cdot d \cdot \cos\theta$, where $d$ is displacement. When a person pushes a wall, the wall does not move, so displacement $d=0$. Substituting $d=0$ into the formula gives $W=0$, meaning no work is done on the wall. The other objects all undergo displacement while a force is applied, so work is done on them.

Answer:

a wall that is being pushed on by a person