A rock is suspended from a string; and it accelerates upward. Which statement is true concerning the tension in the string?
A)The tension points downward.
B)The tension is less than the weight of the rock.
C)The tension is equal to the weight of the rock.
D)The tension is greater than the weight of the rock.
E)The tension is independent of the magnitude of the rock's acceleration.

Question

Quizplus · Accepted Answer

The tension in the string must be greater than the weight of the rock in order to accelerate it upward. This is because tension is the force that must be exerted by the string to counteract the downward force of the weight. Therefore, the tension in the string must be able to provide an additional upward force to accelerate the rock.

A Rock Is Suspended from a String; and It Accelerates