How to calculate the height of a skier

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To calculate the height of a skier, the relationship between potential energy and kinetic energy is utilized, expressed as mgh = 0.5 * m * v^2. The correct velocity to use in calculations must consider its vertical component, particularly when factoring in angles such as 28 degrees. It's crucial to differentiate between the specific height labeled in the problem and the generic height used in equations. Additional information about the skier's condition at the top of the hill, like velocity, is necessary for accurate calculations. Properly applying these principles will lead to the correct determination of height.
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Homework Statement


I want to calculate the height h of the skier in this figure
upload_2016-5-23_16-6-52.png


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)^2Am I doing right ?

Thanks
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JiJiasd said:
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.
 
tommyxu3 said:
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 don't need more!
 
You only got an identity, because you didnt calculate with the right component of speed.
 
thank you all
 
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.
 

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