Question

If a force F = (3i - 2j) N acting on a body displaces it from point (1 m, 2 m) to point (2 m, 0 m), then work done by the force is

• A. 5 J
• B. 6 J
• C. 4 J
• D. 7 J

Hint:

Work done = dot product of force and displacement vectors.

Answer 1

The Correct Option is D

The displacement vector is given by $\vec{d} = (2-1)i + (0-2)j = i - 2j$. The force vector is $\vec{F} = 3i - 2j$. Work done $W = \vec{F} \cdot \vec{d} = (3)(1) + (-2)(-2) = 3 + 4 = 7$ J.