A motor rotates with a uniform angular acceleration. It completes 40 revolutions in 5 s. If its initial angular speed is 300 rpm, what is its final angular speed in rpm?

Step-by-step solution

Initial angular speed, ₀ = 300 rpm = 300 2 60 = 10 rad/s Angular displacement, = 40 revolutions = 40 2 = 80 rad Using the equation of kinematics for rotational motion: = ₀ t + 1 2 t^2 80 = 10 5 + 1 2 (5)^2 80 = 50 + 12.5 = 30 12.5 = 2.4 rad/s ^2 Final angular speed, = ₀ + t = 10 + 2.4 5 = 22 rad/s Converting back to rpm: Final angular speed = 22 60 2 = 660 rpm Answer: 660