Question

A force of 10 N acts on a 2 kg object initially at rest, moving it 8 m along a straight line. What is the work done by the force? Assume the force is parallel to the displacement.

• A. 80 J
• B. 40 J
• C. 120 J
• D. 20 J

Hint:

For work done, use \( W = F \cdot s \cdot \cos \theta \), where \( \theta \) is the angle between force and displacement; if parallel, \( \cos \theta = 1 \).

Answer 1

The Correct Option is A

Given: \[ F = 10 \, \text{N}, \quad s = 8 \, \text{m}, \quad m = 2 \, \text{kg}, \quad \text{initial velocity} = 0 \, \text{m/s} \] Step 1: Formula for Work Done
The work done by a force is given by: \[ W = F \cdot s \cdot \cos \theta \] Since the force is parallel to the displacement, \( \theta = 0^\circ \), and \( \cos 0^\circ = 1 \). Step 2: Calculate Work Done
Substitute the values: \[ W = 10 \cdot 8 \cdot 1 = 80 \, \text{J} \] Thus, the work done is: \[ \boxed{80 \, \text{J}} \]