Question Detail
Question
A force F = 2i - 3j - k N moves a body from r₁ = -2i + 3j + k to r₂ = 3i - 2j - k m. Find the work done.
Correct Answer
Option B is the correct answer.
Detailed Explanation
First find displacement: r = r₂ - r₁ = (3i - 2j - k) - (-2i + 3j + k) = 5i - 5j - 2k. Work is dot product: F·r = (2)(5) + (-3)(-5) + (-1)(-2) = 10 + 15 + 2 = 27 J.
Hint
Work done by a constant force is the dot product of force and displacement vectors.