- #1

- 15

- 0

**Problem With Maximum Acceleration up Hill!!**

## Homework Statement

cross-country skier is going up a slope at angle 5º to the horizontal. She is skating so only her skis provide the propulsion (i.e. she does not push with her ski poles). The static and kinetic friction coefficients for this situation are μs = 0.12, μk = 0.07 respectively.

Find the magnitude of her maximum possible uphill acceleration?

## Homework Equations

Fnet=MA

## The Attempt at a Solution

So Far:

Fnet(x)= F(static) - F(kinetic) - Fg = ma

Fnet(x) = (0.12 x m x 9.8cos85) - (0.07 x m x 9.8cos85) - (9.8cos85 x m) = ma

Divide by m you get:

Fnet(x) = (0.12 x 9.8cos85) - (0.07 x 9.8cos85) - 9.8cos85 = a

Therefore a= - 0.81m/s^2

But this gives me a negative accelleration, Where did I go wrong? as it asks for the Max acceleration up the hill and that acceleration would point down hill.

HELP PLEASE!!!