The angular speed of a motor wheel is increased from `600"rpm"` to `1200"rpm"` in `4` seconds. Calculate how many revolutions does the engine make during this time.

Explanation

Using `omega=omega_(0)+alpha t`
`alpha=(omega-omega_(0))/(t)`
`omega_(0)=600"rpm"`
`=(2pixx600)/(60)=20pi rad s^(-1)`
`omega=1200"rpm"`
`=(2pixx1200)/(60)=40pi rad s^(-1)`
`alpha=(20pi)/(4)=5pi rad s^(-2)`
again using,
`theta=omega_(0)t+(1)/(2)alpha t^(2)`
`theta=20pixx4+(1)/(2)xx5pixx16`
`theta=80pi+40pi=120pi`
Number of revolutions `=(theta)/(2pi)=(120pi)/(2pi)=60` revolutions