A 100-kg object rests on a level surface with a coefficient of friction (both kinetic and static) of 0.40. If the initial velocity is 15m/s and the object comes to rest,

(a) how much friction is acting on the object?
(b) What is the objects 's acceleration due to friction?
(c) How long will it take for it to fome rest
(d) how far will it travel before coming to rest?

2 answers

F = .4 * 100 * 9.81

a = 100

v = 15 - a t

so t = 15/a

average speed = 15/2 = 7.5
d = 7.5 t
a = F/100