Good – or more dangerous – racing drivers are faster than other racing drivers. Towards the end of a race, the slower drivers may find themselves being lapped by other racing drivers who have completed one more circuit than they have.
If the speeds of the racing drivers are
and
with
on a circuit of
miles, how long will it be before the faster driver laps the slower?
The faster driver travels
mph faster than the slower. Suppose the time for the slower driver to be lapped is
hours, then the faster driver will have travelledmiles further.
We can use the equation
with
and speed equal to the relative speed of the drivers,to giver
Suppose that
and
The time for the slower driver to be lapped is then