Question

1. Define energy.
2. State the mathematical expression of work.
3. State two examples of when a force acting on a body does not do any work.

Answer 1

Step 1: Definition of energy

Energy: The capacity (or ability) of a body to do work is called energy.

Step 2: Mathematical Expression of Work:

1. Work is defined mathematically as the product of force and the displacement through which force acts.
2. Work done = Force X Displacement through which the force acts if F is the applied force, 'S' is the displacement in the direction of the applied force, and W is the work done.$W=F\times s$

Step 3: Two examples of when a force acting on a body does not do any work:

1. When we push against a wall, we apply force, yet the wall does not move, hence no labor is done.
2. While standing and carrying your bag, you may be exerting energy, but no work is being done since there is no displacement.