Question

The diameter of a bullock cart wheel is $\frac{14}{11}$ meters. This wheel makes $10$ complete revolutions per minute. What would be the speed of the cart in kilometers per hour?

• A. $4.8$
• B. $9.6$
• C. $8.8$
• D. $2.4$

Answer 1

Answer: (D)

$2.4$

Radius of the wheel $=\frac{1}{2}\times \frac{14}{11}m=\frac{7}{11}m$

Distance covered by wheel in 1 revolution $=$ Circumference of wheel

$=2\times \frac{22}{7}\times \frac{7}{11}=4$ meter

$\therefore$ Distance covered in 10 revolutions $=(4\times 10)=40$ meters

Thus, distance of $40$ meters is covered in one minute i.e. $2400$ meters in 60 minutes i.e. 2.4 km in one hour.

$\therefore$ Speed $=2.4$ km / hour