# Skier down a hill

#### 1MileCrash

1. The problem statement, all variables and given/known data

A 50kg skier skis directly down a frictionless slope angled 16* to the horizontal. Assume the skier moves at a negative x direction. A wind force with component Fx acts on the skier.

What is Fx if the skier's velocity magnitude is constant?

2. Relevant equations

3. The attempt at a solution

I really have no idea. I assume Fx is equal to the force the skier exerts "on the air" so F = ma on the skier.

But I am utterly confused when they say velocity is constant. He is going down the slope due to gravity, how could his velocity be constant? It makes no sense to me.

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#### Spinnor

Gold Member
The negative x direction is the direction the skier goes. There are two forces which act in the x direction on the skier, -sin(16)*m*g and F_x, they are equal and opposite.

#### 1MileCrash

How would I adjust that if the skier's velocity is increasing 10m/s/s?

-sin(16)(5)(9.8 + 10t)
?

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