In a wa 4. 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?
Answers
Given
Diameter of wheel = 80 cm
Time = 10 minutes
Speed = 66 km/hr
Concept used
Circumference of wheel = 2πr
Calculation,
Diameter = 80 cm
Radius = 80/2
Radius = 40 cm
Circumference of wheel = 2πr
Distance covered = Circumference of wheel
Distance = 1760/7 cm
1 cm = 1/100 m
Distance = 176/70 meter
176/70 meter covered in 1 revolution
1 m covered in : 70/176 Revolutions - - (i)
Distance covered in 10 minutes = 66 × 10/60
Distance = 11 km
Distance = 11000 m - - - - - (ii)
So 11000 is covered in =
∴ 4375 revolutions
Answer:
Given
Diameter of wheel = 80 cm
Time = 10 minutes
Speed = 66 km/hr
Concept used
Circumference of wheel = 2πr
Calculation,
Diameter = 80 cm
Radius = 80/2
Radius = 40 cm
Circumference of wheel = 2πr
Distance covered = Circumference of wheel
Distance = 1760/7 cm
1 cm = 1/100 m
Distance = 176/70 meter
176/70 meter covered in 1 revolution
1 m covered in : 70/176 Revolutions - - (i)
Distance covered in 10 minutes = 66 × 10/60
Distance = 11 km
Distance = 11000 m - - - - - (ii)
So 11000 is covered in =
\frac{70}{176} \times 11000
176
70
×11000
∴ 4375 revolutions