Question

A force of 10 N is acting on an object. The object displaces through 5 m in the direction of force. The work done is:
1. 10 Nm
2. 50 Nm
3. 2 Nm
4. 5 Nm

Answer 1

Correct Answer - Option 2 : 50 Nm

CONCEPT:

• Work is said to be done by a force when the body is displaced actually through some distance in the direction of the applied force.
• Since the body is being displaced in the direction of F, therefore work done by the force in displacing the body through a distance s is given by

\(W = \vec F \cdot \vec s\)

W = Fs cos θ

Where θ = angle between force direction of motion

• Thus work done by a force is equal to the scalar or dot product of the force and the displacement of the body.
• SI unit of work is Joule (J).

CALCULATION:

Given - Force (F) = 10 N, displacement (s) = 5 m and, θ = 0° 

• The work done can be calculated as,

⇒ W = Fs cos θ

⇒ W = 10 × 5 × cos 0° = 50 Nm