Question

A block of mass $m$ is directly pulled up slowly on a smooth inclined plane of height $h$ and inclination $\theta$ with the help of a string parallel to the incline. Which of the following statement is incorrect for the block when it moves up from the bottom to the top of the incline?

• A. Work done by the normal reaction force is zero
• B. Work done by the string is $mgh$
• C. Work done by gravity is -$mgh$
• D. Net work done on the block is zero

Answer 1

Answer: (C)