Answer:
The 3rd graph
Step-by-step explanation:
A free body diagram is a diagram which shows all the forces acting on an object.
The problem asks us to find the free body diagram of block A, so we must find all the forces acting on block A.
We have 3 forces acting on block A in total:
- The force of gravity (its weight), which pushes the block downward (in the diagram, it is the force represented with
- The tension in the rope 1, which pulls block A upwards: this force is represented with
- The tension in the rope 2, due to the weight of block 2, which pulls block A downwards: this force is represented with
Based on the direction of these 3 forces, the correct diagram is the 3rd one.