Question:
The angular speed of truck wheel is increased from $900 \mathrm{rpm}$ to $2460 \mathrm{rpm}$ in 26 seconds. The number of revolutions by the truck engine during this time is_______
(Assuming the acceleration to be uniform).
Solution:
(728)
We know, $\theta=\left(\frac{\omega_{1}+\omega_{2}}{2}\right) t$
Let number of revolutions be $\mathrm{N}$
$\therefore 2 \pi \mathrm{N}=2 \pi\left(\frac{900+2460}{60 \times 2}\right) \times 26$
$\mathrm{N}=728$