Question

1. name the missing force... a) weight force b) normal force c) lift d) applied force

Explanation:

The person is pushing the rock, so the missing force is the force applied by the person on the rock. Weight force ($F_g$) is already shown acting down - ward, normal force ($F_N$) is the force perpendicular to the surface, and lift is a force typically associated with fluids and flight. Here, the person is exerting an applied force on the rock.

Answer:

d) applied force