Question

A massless spring with force constant k = 216 n/m hangs from the ceiling. A 2.9 kg block is attached to the free end of the spring and released. If the block falls 11 cm before starting back upwards, how much work is done (in J) by friction during its descent?

Answer 1

The work done by friction during the descent of the block is zero joules.

Step-by-step explanation:

To calculate the work done by friction during the descent of the block, we need to understand the forces acting on the block. Initially, the block is at rest, and the only force acting on it is the force of gravity. As the block falls, the spring compresses and exerts an upward force on the block, counteracting the force of gravity. Once the block reaches its lowest point and starts moving upwards, the force of the spring becomes greater than the force of gravity, causing the block to accelerate upwards.

Since the block is not in equilibrium at any point during its descent, the work done by friction can be considered negligible. Frictional forces typically arise when there is relative motion between two surfaces in contact, and in this case, the block is sliding freely without any friction. Therefore, the work done by friction during the descent of the block is zero joules.