Question

An automobile with 0.279 m radius tires travels 65000 km before wearing them out. How many revolutions do the tires make, neglecting any backing up and any change in radius due to wear? (You do not need to enter any units.)

Answer 1

Revolutions=37079108.61 rev

Explanation:

First if all we have to make the units same to calculate the revolutions

Since distance gis gien in km and radius is given in m we will covert distance to m first.

Distance =S=65000km

Distance=S=65000km*1000m/km

Distance = S= 65000000m

Formula:

S=rθ

where

S is the distance

r is the radius

θ is the revolution in radian

θ=S/r

θ=65000000/0.279

θ=232974910.4 rad

Revolutions=θ/2π

Revolutions=232974910.4/2π

Revolutions=37079108.61 rev