Question

36. The wheel of a car is of radius 35cm. Find the number of rotations per
minute that it makes to keep a speed of 66km/hr.​

Answer 1

Answer:

500 rotations per minute

Step-by-step explanation:

The radius of the wheel of a car, r= 25 cm.

So, the perimeter of the wheel = 2πr =$\frac{2*22*35}{7}$ =220 cm.

Therefore, the wheel can move 220 cm. per rotation.

Now, it is given that the car has to keep a speed of 66 km/hr.

i.e. a speed of $\frac{66*100000}{60}$ cm per minute.

=11×$10^{4}$ cm per minute.

Hence, the number of rotations per minute required for the wheel to keep this speed of the car will be

$\frac{110000}{220}$ rotations per minute

=500 rotations per minute. (Answer)