Question

A 1,100 kg car is traveling at 15 m/s when the brakes are suddenly applied. How far a distance will it travel if the brakes can exert a force of 6,000 N?

Answer 1

F=ma, so a = -5.45 m/s^2

15+at=0 so t = 0.92 s

s(t) = 15t+ 1/2 at^2
= 15*0.92 - 5.45/2 * 0.92^2 = 11.49 m

Answer 2

F = m a
braking so -
-6000 = 1100 a
a = -5.45 m/s^2

v = Vi + a t
at stop
0 = 15 -5.45 t
t = 2.75 seconds to stop

average speed during stop = 15/2 = 7.5 m/s


d = 7.5 * 2.75 = 20.6 meters

Answer 3

Not sure where that 0.92 came from, now why it didn't trigger a sanity check.

Go with Damon, as usual.