which free body diagram(s) show an object which is clearly accelerating? a. i, ii, iii, iv, v b. i, ii, iv…

Explanation:

Step1: Recall Newton's second law

According to Newton's second law $F = ma$, an object accelerates when there is a non - zero net force acting on it.

Step2: Analyze free - body diagram i

In diagram i, the upward and downward forces are equal in magnitude, so the net force $F_{net}=0$, and the object is not accelerating.

Step3: Analyze free - body diagram ii

In diagram ii, the upward force is larger than the downward force. So, there is a non - zero net force in the upward direction, and the object is accelerating upward.

Step4: Analyze free - body diagram iii

In diagram iii, the upward force is larger than the downward force. So, there is a non - zero net force in the upward direction, and the object is accelerating upward.

Step5: Analyze free - body diagram iv

In diagram iv, there is only a downward force. So, there is a non - zero net force in the downward direction, and the object is accelerating downward.

Step6: Analyze free - body diagram v

In diagram v, the horizontal forces cancel each other out, but the upward force is larger than the downward force. So, there is a non - zero net force in the upward direction, and the object is accelerating upward.

Answer:

C. ii, iii, iv, v