Concepts Of Physics MCQ Edition [Volume 1]PhysicsWork and Energy
A particle travels from a position r ₁ = (2 m ) i + (3 m ) j to a new position r ₂ = (3 m ) i + (2 m ) j while experiencing a force F = (5 N ) i + (5 N ) j . Determine the work done by this force on the particle over the displacement.
Options
- A10 J
- B25 J
- C50 J
- D0 J
Correct answer
D. 0 J
Step-by-step solution
The displacement vector of the particle is given by: r = r ₂ - r ₁ r = (3 i + 2 j ) - (2 i + 3 j ) r = i - j m The work done by the constant force is the dot product of the force and the displacement: W = F r W = (5 i + 5 j ) ( i - j ) W = (5)(1) + (5)(-1) W = 5 - 5 = 0 J