Question

The circumference of a wheel is 9m 75 dm and it turns 4times per second find the time taken by the wheel to cover 390 km

Answer 1

Hello user...
Your answer is here..

First of all we need to convert the units given into a common one...
Let us say distance in metres and time in seconds...
So the data is...
Distance to be covered-390,000m
circumference of the wheel-9+7.5=16.5m
Distance covered in one second = 4*16.5=66m
(because the wheel turns four times per second)

Now required time will be

Total distance/distance covered in one second
i.e. Time,t= 390000/66
- t= 5909.1 seconds(rounded off)
Or time =5909.1/3600 hrs