Question

the diameter of the wheel of a bicycle is 0.45 metre. find the speed of the cycle if the wheel makes 350 revolutions per minute

Answer 1

Given, d= 45/100=9/20 m
No. of revolutions/min=350
Now, C=πd
=22*9/7*20=11*9/7*10=99/70 m
Therefore, the cycle covers 99/70 * 350 m per minute=495m
Therefore, speed=distance/time
=495/1minute=495/60sec=8.25m/sec (1min=60sec)

Answer 2

The diameter of the wheel is 0.45m, and it makes 350 revolutions every minute. This means that the circumference of the bycicle is $\pi0.45$≈1.41.
It makes 350 revolutions every minute, so it has travelled $1.41*350$≈494.8mtrs.
This means that it has gone 494.8 mtrs in a minute.

The answer is 494.8mtrs/minute or 29.688km/hour.