Question

A flywheel rotates about a fixed axis and slows down from $300$ rpm to $100$ rpm in $2$ minutes. Then its angular retardation in radian/minute' is:

Answer 1

${\omega }_f={\omega }_i+at$

${\omega }_f=$ final angular velocity

${\omega }_i=$ initial angular velocity

$\omega =$ angular acceleration, $t=$time

Insorting values we get

$100=300+9\times 2$

$\Rightarrow a=-100\frac{relation}{mi{n}^2}$

[-denotes reterdation]

As each rotation consists of $2\pi$ radian

So $a=-100\times 2x\frac{radian}{(min{)}^2}$

$=-200\pi \frac{radian}{(min{)}^2}$