# How to calculate the height of a skier

## Homework Statement

I want to calculate the height h of the skier in this figure ## Homework Equations

potential energy and kinetic energy and there is no friction

## The Attempt at a Solution

mgh = 0,5 *m*v^2
v=√ (2*g*h)

Now calculate the h when he goes up

mgh= 0,5 *m*√ (2*g*h)^2

Am I doing right ?

Thanks

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## Answers and Replies

Now calculate the h when he goes up

mgh= 0,5 *m*√ (2*g*h)^2
What you got is an identity. You need more information of the person on the top of the hill to get his condition, such as velocity~

mgh = 0,5 *m*v^2
v=√ (2*g*h)

This is right but after this, only calculate with its vertical component (v*sin(28 deg)), when calculating h.

What you got is an identity. You need more information of the person on the top of the hill to get his condition, such as velocity~
These informations are enough, you dont need more!

You only got an identity, because you didnt calculate with the right component of speed.

thank you all

haruspex
Science Advisor
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You need to be careful with 'h'. There is a specific height in the problem which is labelled h, and there is the generic h in the equation gh=v2/2. Don't get them mixed up.
First, find the velocity at the launch point.