Question: An electric motor exerts a constant torque 10N –m on a grind stone mounted on a shaft. NOI of the gr...

Question

An electric motor exerts a constant torque 10N –m on a grind stone mounted on a shaft. NOI of the grind stone about the shaft is 2kg m². If the system starts from rest find the work done in 8 s.

Answer 1

Solution

α = $\frac{\tau}{I} = \frac{10}{2}$ = 5 rad/s².

ω = ω₀ + αt = 5(8) = 40 rad s^-1

W = ∆KE = $\frac{1}{2}$ Iω² – 0 = $\frac{1}{2}$ × 2 × (40)² = 1600 J