Question

A crane lifts up two boxes.

A picture of a crane with a cable hanging down labeled Rope 1, which is attached to a box labeled A. Box A is attached to a cable labeled Rope 2, which is attached to a box labeled B.

Which free body diagram shows the forces acting on block A?

A free body diagram with two force vectors, the first pointing downward labeled F Subscript g A Baseline, the second pointing upward labeled F Subscript T 1 Baseline.
A free body diagram with three force vectors, the first pointing downward labeled F Subscript g A Baseline, the second pointing upward labeled F Subscript T 1 Baseline, and the third pointing downward labeled F Subscript g B.
A free body diagram with three force vectors, the first pointing downward labeled F Subscript g A Baseline, the second pointing upward labeled F Subscript T 1 Baseline, and the third pointing downward labeled F Subscript T 2.
A free body diagram with three force vectors, the first pointing downward labeled F Subscript g A Baseline, the second pointing upward labeled F Subscript T 1 Baseline, and the third pointing upward labeled F Subscript T 2.

Answer 1

The diagram with three forces: downward F_gA, upward F_T1, and downward F_T2.

Explanation: A feels its own weight downward, the top rope's tension T1 pulling it up, and the lower rope's tension T2 pulling it down (T2 pulls A downward while it pulls B upward).