Question 743502
the stopping distance,s, of a car varies directly as the square of its speed, v.
 If a car traveling 60mph requires 220 ft. to stop,what is the stopping distance for a car traveling 30 mph.
:
let s = stopping distance at 30mph, write a ratio equation
{{{s/220}}} = {{{30^2/60^2}}}
{{{s/220}}} = {{{900/3600}}}
Reduce fraction
{{{s/220}}} = {{{1/4}}}
cross multiply
4s = 220
s = 220/4
s = 55 ft to stop at 30 mph