Calculating Total Energy of a High Diver's Leap

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Homework Help Overview

The problem involves a high diver with a mass of 50kg who has 10,000 Joules of gravitational potential energy at a height of 20m. The question focuses on determining the total energy of the diver when he has descended three-quarters of the height of the diving platform, specifically looking at the relationship between kinetic and potential energy during the dive.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants express uncertainty about how to calculate kinetic energy without knowing the speed. There are inquiries about applicable equations for conservation of energy and the relationship between potential and kinetic energy. Some participants suggest that potential energy may convert into kinetic energy during the dive.

Discussion Status

The discussion has seen participants questioning the equations available to them and exploring the concept of energy conservation. Some guidance has been offered regarding the conservation of mechanical energy throughout the dive, but no consensus has been reached on the specific calculations needed.

Contextual Notes

Participants mention a lack of prior discussion on potential energy and conservation of energy in their class, which may be influencing their understanding of the problem.

lbella026
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Homework Statement


A high diver, mass 50kg sits atop the diving platform with 10,000 Joules of stored gravitational potential energy (PE). The platform has a height of 20m. The diver makes his leap. When the diver has dropped 3/4 of the height what is diver total energy (KE + PE).


Homework Equations


KE=(1/2)mass x speed squared


The Attempt at a Solution


I don't know how to find the Kinetic energy using the equation without knowing the speed.
 
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lbella026 said:

Homework Statement


A high diver, mass 50kg sits atop the diving platform with 10,000 Joules of stored gravitational potential energy (PE). The platform has a height of 20m. The diver makes his leap. When the diver has dropped 3/4 of the height what is diver total energy (KE + PE).


Homework Equations


KE=(1/2)mass x speed squared


The Attempt at a Solution


I don't know how to find the Kinetic energy using the equation without knowing the speed.

Have you "guys" done any conservation of Energy problems?
 
We haven't yet. I'm unsure of what equation to use which would apply. That equation and the W=force x distance are the only ones I can find in the book. Is there another equation I could use? thanks!
 
lbella026 said:
We haven't yet. I'm unsure of what equation to use which would apply. That equation and the W=force x distance are the only ones I can find in the book. Is there another equation I could use? thanks!

So you have not talked about Potential Energy, or gravitational potential energy in class? Along with F x d = Work and Kinetic energy?
 
ohhh would the potential energy be the same as the kinetic energy?? KE =10,000 J. would the potenial energy be lost and kinetic energy gainned?
 
lbella026 said:
ohhh would the potential energy be the same as the kinetic energy?? KE =10,000 J. would the potenial energy be lost and kinetic energy gainned?

The diver has the same amount of Mechanical energy (PE + KE) or (U + K) all the way through his dive. His mechanical energy is conserved.

So if the diver is not moving he has all his energy in the form of potential energy. If the diver is moving and he is above the lowest point in his path he has potential energy and kinetic energy (yes some potential energy is now kinetic energy). And at the lowest point in the path he is moving his fastest, all his potential energy is now kinetic energy. But at every position the total energy is the same.
 
ok now I understand. Thank you so much!
 

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