Question

The diameter of a car wheel is 60 cm, if the car travels at an average speed of 13.2m/s, find the number of revolutions made by the car per hour , hiving the awnser correct to nearest whole number.(take pie to be 3.142 )

Answer 1

Given :

The diameter of a car wheel is 60 cm, if the car travels at an average speed of 13.2m/s,

To Find :

find the number of revolutions made by the car per hour , hiving the awnser correct to nearest whole number.(take pie to be 3.142 )

Solution:

Diameter of car wheel= 60 cm

Radius of car wheel = $\frac{60}{2}=30 cm$

Circumference of wheel = $2 \pi r = 2 \times 3.14 \times 30=188.4 cm =1.8852 meters$

Distance covered in 1 revolution =1.8852 meters

Speed of car = 13.2 m/s

Time = 1 hour =3600 seconds

Distance covered in one hour =$3600 \times 13.2 =47520 meters$

No. of revolution in 1.8852 meters = 1

No. revolutions in  47520 m= $\frac{47520}{1.8852}=25206.874$

So, 25207 revolutions made by car in 1 hour

Answer 2

Step-by-step explanation:

Diameter of car wheel= 60 cm

Radius of car wheel = \frac{60}{2}=30 cm260=30cm

Circumference of wheel = 2 \pi r = 2 \times 3.14 \times 30=188.4 cm =1.8852 meters2πr=2×3.14×30=188.4cm=1.8852meters

Distance covered in 1 revolution =1.8852 meters

Speed of car = 13.2 m/s

Time = 1 hour =3600 seconds

Distance covered in one hour =3600 \times 13.2 =47520 meters3600×13.2=47520meters

No. of revolution in 1.8852 meters = 1

No. revolutions in  47520 m= \frac{47520}{1.8852}=25206.8741.885247520=25206.874

So, 25207 revolutions made by car