Question

The wheels of a car are of diameter 80 cm each. How many complete revolutions does
each wheel make in 10 minutes when the car is travelling at a speed of 66 km per hour​

Answer 1

Answer:

Step-by-step explanation:The wheels of car of diameter = 80 cm

Radius of wheel = Diameter/2 = 80/2 = 40 cm

Circumference of circle = 2πr

⇒ 2 × 22/7 × 40

⇒ 80 × 22/7

We have to find the number of revolutions taken by each wheel in 10 min.

We know that, 1 hour = 60 min

So, 10 min = 1/6 hrs.

Now,

Distance = Speed × time

Given that, car is travelling at a speed of 66 km/hr.

⇒ 66 × 1/6

⇒ 11 km

Therefore, distance covered by car in 10 min is 11 km.

We also know that,

1 km = 1000 m

1 m = 100 cm

So, 1 km = 100000 cm (1000 × 100)

Therefore, 11 km = 1100000 cm

Distance covered by car is 1100000 cm.

Now,

Number of revolutions = Distance covered by car/Circumference of car

⇒ 1100000/(80 × 22/7)

⇒ (1100000 × 7)/(80 × 22)

⇒ 4375

Therefore, total number of revolutions taken by each wheel in 10 min is 4375 when the car is travelling at a speed of 66 km/hr.