Question

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

Explanation:

The forces shown are the gravitational force ($F_g$), normal force ($F_N$), and frictional force ($F_f$). In the context of a person interacting with the rock, there is an external push or pull which is an applied force. The weight force is $F_g$, the normal force is $F_N$, and lift is not relevant here. The missing force is the applied force by the person on the rock.

Answer:

d) applied force