Hi,
You have not mentioned here a very imprtant quantity : time.
Well this can be solved using average velocity.
avg. velocity = (v + u)/2 where v is final velocity and u is initial velocity.
Also avg. velocity = distance/time
in our case initial velocity is 20 miles/hr and final velocity is zero but time is not mentioned.
so (0 + 20)/2 = distance/time
so distance = 10 * time.
The distance will be in miles as velocity is mentioned in miles/hr.
Regards Abhi
