Question

The wheel of a motorcycle is of a radius of 35 cm. The number of revolutions per minute must the Wheel made so as to keep a speed of 66 km/h is ___________

Answer 1

Step 1: Given

The radius of the wheel, $r=35cm=0.35m$

Speed of the motorcycle, $s=66km/h$

Step 2: Formula Used

Speed

1. It s the rate of change of distance per unit of time.

$n=\frac{d}{C}$

Where $d$ is the distance traveled in one min and $C$ is the circumference of the wheel.

Step 3: The number of rotation per minute:

Converting speed from km/h to m/min

$\Rightarrow d=\frac{66\times 1000}{60}=1100m/min$

$Thecircumferenceofthewheel=2\pi r$

$Thecircumferenceofthewheel=2\times \frac{22}{7}\times 0.35m$

$Thecircumferenceofthewheel=2.2m$

According to the speed of the motorcycle,

Distance traveled by wheels in 1 minute = $1100m$

Now,

$thedis\tan cecoveredbyawheelinonerevolution=thecircumferenceofthewheel$

Therefore the number of revolutions, $n=\frac{d}{C}$

$\Rightarrow n=\frac{1100}{2.2}$

$\Rightarrow n=500$

So, The wheel of a motorcycle is of a radius of 35 cm. The number of revolutions per minute must the Wheel made so as to keep a speed of 66 km/h is 500 revolutions.