The armature (or spinning portion) of a motor is accelerated uniformly from rest to a rotational velocity of 1500 rev/min in 10 seconds. The rotational acceleration of the motor is A) 150 rad/s². B) 15.7 rad/s². C) 31.4 rad/s². D) 75 rad/s². E) zero.

Question

Quizplus · Accepted Answer

First, we need to convert the final rotational velocity from rev/min to rad/s:

1500 rev/min = (1500 rev/min) * (2π rad/rev) * (1 min/60 s) = 157.08 rad/s

Then, we can use the formula:

rotational acceleration = (final rotational velocity - initial rotational velocity) / time

Since the motor starts from rest, the initial rotational velocity is 0. Plugging in the given values, we get:

rotational acceleration = (157.08 rad/s - 0) / 10 s = 15.7 rad/s^2

Therefore, the answer is B.

The Armature (Or Spinning Portion) of a Motor Is Accelerated