Iceskating up a Hill: Determining Height with Initial Velocity and Friction

[Gurkis]

Homework Statement

An iceskater weighing 69kg is gliding up an incline hill at 20 degrees.
How high up does the skater make it when her initial velocity is 8,9m/s and the friction between her skates and the ice is 0,97N.

Homework Equations

mg(y) = m*g*cos(20)
mg(x) = m*g*sin(20)

The Attempt at a Solution

F(friction) = $\mu$ * mg(y)

F$\rightarrow$ = F(f) + F(mg(x))

a=F$\div$M$\rightarrow$F$\div$m=232,7$\div$69 = 3,34m/s^2

s = (v^2 - v(o)^2) / 2a = 11,8m

sin(20)*11,8=4,05...$\approx$ 4,1m

the answer should be 4,0m. What am I doing wrong?

 

[PhanthomJay]

Physics looks good, maths is off...redo the math: you should get something like 4,02 which rounded to two sig figs is 4,0

 

[Gurkis]

I see, thanks. I thought my problem was that I was thinking about it all wrong. I redid the math and it checks out.

Appreciate the help!