Question Detail
Question
A wheel of radius 0.6 m has moment of inertia 5 kg·m². A constant force of 60 N is applied tangentially. Find the work done in 4 s (starts from rest).
Correct Answer
Option B is the correct answer.
Detailed Explanation
Work W = Torque × angular displacement. Torque = F × r = 60×0.6=36 Nm. Angular acceleration α = τ/I = 36/5=7.2 rad/s². θ = 0.5 α t² = 0.5×7.2×16=57.6 rad. W = τθ = 36×57.6 ≈ 2073 J.
Hint
Use W = τθ and θ = 0.5 α t².