Question

The wheel of a motor cycle is of radius $35cm$. How many revolutions per minute must the wheel make so as to keep a speed of $66km/hr$?

Answer 1

Solution-

Speed $=66km/hr$

Speed $cm/min=\frac{66\times 1000\times 100}{60}=110000cm/min$

Circumference of wheel $=2\pi \times 35$

$2\times \frac{22}{7}\times 35=220cm$

No. of revolution per minite $=\frac{110000}{220}$

$=500$ revolution per min.