A heavy block at rest is suspended by a vertical rope. When the block accelerates upward by the rope, the rope tension
A)is less than its weight.
B)equals its weight.
C)is greater than its weight.

Question

Quizplus · Accepted Answer

Since the block is accelerating upwards, there must be a net upward force acting on it. The only upward force acting on the block is the tension in the rope, so the tension must be greater than the weight of the block. This is also consistent with Newton's second law, which states that the net force on an object is proportional to its acceleration: T - mg = ma, where T is the tension, m is the mass of the block, g is the acceleration due to gravity, and a is the upward acceleration of the block. Rearranging the equation, we get T = m(g + a), which shows that the tension is greater than the weight of the block (mg) when a is positive.

A Heavy Block at Rest Is Suspended by a Vertical