physics problem!?

Question

On a frozen pond, a 10kg sled is given a kick that imparts an initial speed of 2m/s, the coefficient of kinetic friction between sled and ice is .10.
a. find the distance the sled moves before coming to rest.
b. the mechanical energy lost due to friction

Answer 1

for part A: simply used the equations of motion as derived from newtons second law.
F=ma, X(t)=.5at^2+vt+x, V(t)=at+v
-->a=-.1*2=-.2, v=10, x=0
solve for t by setting V(t)=0, then plug that answer in for t in
X(t) and solve for X(t)
B: intial KE minus final KE
intial KE=.5mv^2
final KE=0

Answer 2

a.
Ff = 0.1W = 0.1Mg
opposing the direction of motion,
a = Ff/M = - 0.1g
V^2 - Vo^2 = 2as
s =(0 - 2^2)/(- 0.1)(9.80665) m

b.
KE = (1/2)MV^2
Since the sled comes to rest, all KE is lost:
KE = (1/2)(10)(2^2) kg-m/s^2