What is the relationship between kinetic energy and gravitational acceleration?

AI Thread Summary
The discussion focuses on understanding the relationship between kinetic energy (KE) and gravitational acceleration (g) through the Law of Conservation of Energy. The user seeks clarification on how to demonstrate that the slope of KE/m versus height (y) equals -g and how to calculate gravitational acceleration with uncertainty. Responses suggest using the formula for the conservation of energy, specifically the relationship between loss in gravitational potential energy (GPE) and gain in KE. Additionally, guidance is provided on calculating uncertainties in the context of the data analysis. This conversation emphasizes the importance of mathematical proof and data support in the lab report.
Makali
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Hello.

I am in a 100 level physics college course and we are learning about conservation of energy. I am working with a program called Logger Pro. I've attached my data in the pictures. Here is a question that I am very much stuck on.

Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g

I also need to figure out gravitational acceleration +/- uncertainty.

If more information is needed, please let me know. Thanks in advance for your help! <3
 

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Makali said:
Hello.

I am in a 100 level physics college course and we are learning about conservation of energy. I am working with a program called Logger Pro. I've attached my data in the pictures. Here is a question that I am very much stuck on.

Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g

I also need to figure out gravitational acceleration +/- uncertainty.

If more information is needed, please let me know. Thanks in advance for your help! <3

Hi, welcome to PF!

From what I can see, your data and graphs plotted have indeed shown that KE/M is -g, so I'm not sure what you are asking for exactly. Are you asking for mathematical proof?
 
I am just confused on what I need to write in my lab report to be honest. Like, is Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g, the slope plus the uncertainty in one of the graphs? I'm just confused haha
 
Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g: I also need to figure out a mathematical equation for my data analysis section.
 
Makali said:
I am just confused on what I need to write in my lab report to be honest. Like, is Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g, the slope plus the uncertainty in one of the graphs? I'm just confused haha
Ah okay

For your lab report i think you need to use mathematical formulae to prove that first, then say it is supported by your data

Consider using: Loss in GPE = gain in KE
 
Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g

Is that the slope and uncertainty of one of the graphs?

What mathematical formula can I use to answer
Using the Law of Conservation of Energy, show that the slope of KE/m vs. y is the gravitational acceleration -g:
 
Makali said:
What mathematical formula can I use to answer
:

This:
Alloymouse said:
Consider using: Loss in GPE = gain in KE

I presume you know how KE and GPE are computed (1/2 mv^2, mgh)?

From there you should be able to do some quick algebra and swap the variables around to get KE/m = -g

For uncertainty, I believe you might find googling "fractional uncertainties" and "how to calculate uncertainty in an equation" helpful
 
Thank you.
 
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