Question:
The wheel of a cart is making 5 revolutions per second. If the diameter of the wheel is 84 cm, find its speed in km per hour.
Solution:
Distance covered in 1 revolution $=\pi \times d$
$=\left(\frac{22}{7} \times 84\right) \mathrm{cm}$
$=264 \mathrm{~cm}$
Distance covered in 1 second $=(5 \times 264) \mathrm{cm}$
$=1320 \mathrm{~cm}$
Distance covered in 1 hour $=(60 \times 60 \times 1320) \mathrm{cm}$
$=4752000 \mathrm{~cm}$
$=\left(\frac{4752000}{1000 \times 100}\right) \mathrm{km}$
$=47.52 \mathrm{~km}$
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.