Calculating Total Energy of a High Diver's Leap

In summary: 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.
  • #1
lbella026
7
0

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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  • #2
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?
 
  • #3
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!
 
  • #4
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?
 
  • #5
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?
 
  • #6
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.
 
  • #7
ok now I understand. Thank you so much!
 

What is kinetic energy?

Kinetic energy is the energy possessed by an object due to its motion.

How is kinetic energy calculated?

Kinetic energy is calculated using the formula KE = 1/2 * m * v^2, where m is the mass of the object and v is its velocity.

What are the units of kinetic energy?

The SI unit for kinetic energy is Joules (J). It can also be expressed in terms of other units such as kilogram-meters squared per second squared (kg*m^2/s^2).

What factors affect an object's kinetic energy?

An object's kinetic energy is affected by its mass and velocity. The greater the mass and velocity, the greater the kinetic energy.

Why is kinetic energy important?

Kinetic energy plays a crucial role in various physical phenomena such as collisions, motion, and heat transfer. It is also an essential concept in understanding the laws of thermodynamics and energy conservation.

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