Question

You lift a heavy book from the floor of the room and keep it in the bookshelf having a height of 2m. This process takes 5 seconds. The work done by you will depend on

• A. Mass of the book and the time taken
• B. Weight of the book and height of the bookshelf
• C. Height of the bookshelf and the time taken
• D. Mass of the book, height of the bookshelf and the time taken

Hint:

Work done is determined by the force applied and the displacement, not the time taken.

Answer 1

The Correct Option is B

Step 1: Understand the formula for work done.
The work done in lifting the book is given by: \[ W = F \times d \] where \( F \) is the force exerted (which is the weight of the book), and \( d \) is the displacement (which is the height of the bookshelf).

Step 2: Work done depends on the weight of the book and the height.
The weight of the book \( W = mg \), where \( m \) is the mass and \( g \) is the acceleration due to gravity.
Therefore, the work depends on the weight and height.
Time does not affect the work done, only the power.