Question

The Wheels of a car is 80 CM in diameter how many complete Revolution does each wheel will make in 8 minutes if car is travelling at a speed of 33 km per hour

Answer 1

Radius of wheel= 80/2 = 40cm

∴ The distance travelled in one revolution is = 2πr = 2 x 22/7 x 40 = 1760/7 cm.

 

speed of car= 66km/hr= 66 x 1,00,000/60 cm/min = 1,10,000 cm/min.

distance covered by car in 1 min = 1,10,000 cm

distance covered by car in 10 min =  110,000 x 10 = 11,00,000 cm.

number of complete revolution =

              distance covered in 10 min / distance covered in one revolution.

= 11,00,000/ 1760/7 

                     = 11,00,000/1 x 7/1760 = 4375 revolutions.

Hence, in 10 min each wheel of car makes 4375 revolutions.