Question

An automobile tire is rated to last for 60,000 miles. to an order of magnitude, through how many revolutions will it turn?

Answer 1

Let the average diameter of the automobile tire is about 2 feet. Therefore its circumference is
`2 feet* \pi =6.29 feet`.

Now we have to convert an automobile tire is rated to last for 60,000 miles in to feet.

As
`1 miles =5280 feet` .

So,
`60000 miles = 60000* 5280 feet =316800000 feet`

Thus the number of revolutions,

`(316800000 feet )/(6.29 feet) =50365659.8 revolutions \\\\=5.0*10^7 rev`

Hence, order of magnitude of revolutions is 7.