Question

multiple select question
select all that apply
the figure on the right contains six free-body diagrams. which of the diagrams represent an object that has some acceleration in the vertical direction?
□f
□d
□a
□c
□b
□e

Explanation:

An object has vertical acceleration when the net vertical force is non-zero (Newton's second law: $F_{net}=ma$). We analyze each diagram:

• A: Only horizontal forces, vertical forces = 0 → no vertical acceleration.
• B: Only horizontal forces, vertical forces = 0 → no vertical acceleration.
• C: Vertical forces are unbalanced (downward force, no upward force) → net vertical force exists → vertical acceleration.
• D: Only horizontal forces, vertical forces = 0 → no vertical acceleration.
• E: Vertical forces are unbalanced (two opposing vertical forces of equal size? No, wait: the arrows show vertical forces, but they are equal and opposite? No, no—wait, C has a downward vertical force with no upward counter, E has equal vertical forces? No, no, C has a downward arrow (net downward force), E has up and down arrows that are equal (net vertical force 0). Wait, correction:
• C: Has a downward vertical force, no upward force → net vertical force ≠0 → vertical acceleration.
• E: Vertical forces are equal and opposite → net vertical force =0 → no vertical acceleration.
• F: No vertical forces → net vertical force=0 → no vertical acceleration.

Only diagram C has a non-zero net vertical force, so it is the only one with vertical acceleration.

Answer:

□F
□D
□A
☑C
□B
□E