Question

A disk is initially at motionless, then a motor is turned on and the disk begins to spin. If second the angular acceleration of the disk is a constant 3.5 r a d / s 2 , how many complete revolutions does the disk make in 9 seconds?

Answer 1

The number of revolutions is 301

Step-by-step explanation:

Angular acceleration, α = 3.5 rad/s

Time, t = 9s

Number of revolutions, n = ?

We know,

`\alpha = (w)/(t)`

where,

ω = angular velocity

t = time

It can also be written as:

`\alpha = (\pi n)/(t X 30)`

On substituting the value, we get:

`3.5 = (\pi X n)/(9 X 30) \\\\n = 300.8`

Therefore, the number of revolutions is 301