A 4.0kg bundle starts up a 30degree incline with 128J of?

Question

A 4.0kg bundle starts up a 30degree incline with 128J of kinetic energy. Howfar will it slide up the incline if the coefficient of kinetic friction between bundle and incline is 0.30?

Answer 1

Weight of bundle=4*g
Weight component normal to the incline=
4gcos30.

Force of friction,f =uR where R is the force normal to the incline
or 4gcos30.

Substitute given values:
f=0.30*4gcos30
=10.2N

KE is given as equal to 128J.
Work=f*s, where s is our unknown

Based on principle of conservation of energy:

KE=Work
128=10.2s
s=128/10.2
=12.5m