Finding height using Conservation of Energy

Click For Summary

Homework Help Overview

The problem involves a skier sliding down a ski jump and taking off horizontally, with the goal of finding the height using conservation of energy principles. The scenario includes parameters such as mass, height, and distance traveled.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of the skier's velocity as they leave the cliff, with one participant initially reporting a high speed and another questioning its validity. There is a subsequent correction of the speed and a mention of a formula used to find it.

Discussion Status

The discussion is active, with participants revisiting calculations and sharing insights on the velocity of the skier. There is a recognition of the need to verify assumptions and calculations, leading to a revised understanding of the problem.

Contextual Notes

Participants are working under the assumption of negligible friction and are exploring the implications of energy conservation in the context of the problem. There is a focus on the accuracy of the initial calculations and the formulas used.

Kajayacht
Messages
27
Reaction score
0

Homework Statement


A skier (m=61.00 kg) starts sliding down from the top of a ski jump with negligible friction and takes off horizontally. If h = 6.70 m and D = 9.80 m, find H.

I already found the velocity as he leaves the cliff to be 29.2 m/s

Here's a picture of it: http://img264.imageshack.us/my.php?image=prob21agz5.gif

Homework Equations


E[1] + W[non conservative] = E[2]
K= .5mv^2
U= mgh


The Attempt at a Solution



w[nc]= 0 (no friction)
K[1]= 0, U[2] = 0 so K[2] = U[1]

K[2]= .5*61*29.2^2
K[2]= 26005.52

26005.52 = mgH
26005.52/ (61*9.8) = H
H=43.5
 
Physics news on Phys.org
I already found the velocity as he leaves the cliff to be 29.2 m/s

Can you show how you got this? That's a pretty high speed.
 
You're right, and after reworking I found the speed to be 8.38 m/s which gave me the right answer
 
which I found using V= d* (square root of( g/2h))
 
That looks much better!
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
951
Replies
7
Views
2K
Replies
6
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 9 ·
Replies
9
Views
1K
  • · Replies 5 ·
Replies
5
Views
978
  • · Replies 5 ·
Replies
5
Views
2K