Question

A youngster shoots a bottle cap up a 15.0° inclined board at 1.92 m/s. The cap slides in a straight line, slowing to 0.95 m/s after traveling some distance. If the coefficient of kinetic friction is 0.35, find that distance.

I still get 0.315 m as the answer, but it's incorrect. What am I doing wrong?

Answer 1

If you say the final speed is zero, where it stops, then .315 meters is correct
However the final speed is .95 m/s, not zero. That gives me .238 meters.
I will type it up in a minute.

Answer 2

F = m g (.35cos 15 + sin15)
F = m (9.8) (.5969)
a = F/m = 5.85 m/s^2 down the ramp
Vo = 1/92 m/s
Vf = .95 m/s

v = Vo - 5.85 t
.95 = 1.92 - 5.85 t
t = .1658

x = 1.92 t - .5 (5.85) t^2
x = .318 - .0804
x = .238

Answer 3

Ahhh ok that was what was wrong.
Thanks a ton. :)