What net force would actually be necessary to stop an automobile of mass 880 traveling initially at a speed of 52.0 in a distance equal to the diameter of a dime, which is 1.8 ?

Question

What net force would actually be necessary to stop an automobile of mass 880  traveling initially at a speed of 52.0  in a distance equal to the diameter of a dime, which is 1.8 ?

Damon · Answer

You gave no units.
I will assume 880 kg
52 m/s
1.8 cm which is .018 meters
F = m a so we need a
v = Vi + a t
0 = 52 + a t
so a t = -52
a =-52/t
then
d = (1/2) a t^2
.018 = (1/2) (-52/t) t^2
t = .018/26 = 6.92 * 10^-4
so
a = -52/t = -52 /(6.922*10^-4)
then
F = 880 a

drwls · Answer

This question was asked three days ago, with the proper units included. See http://www.jiskha.com/display.cgi?id=1268561532