Energy transfer question (Use PE=KE or SUVAT ?)

AI Thread Summary
An object falling from a height of 3 meters can be analyzed using both potential energy (PE) and kinetic energy (KE) equations, as well as SUVAT equations. The initial calculation using PE=KE yielded a velocity of 7.66 m/s, while the SUVAT method initially produced an incorrect result of 17.15 m/s due to a miscalculation. Upon re-evaluation, the SUVAT method confirmed the same result as the PE=KE approach, demonstrating that both methods can yield consistent answers when applied correctly. The discussion emphasizes the importance of careful calculations and understanding the principles behind energy transfer and motion equations. Both methods are valid for solving the problem, provided the calculations are executed accurately.
CannonSLX
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Homework Statement


Object falls from a tree which is 3m above the ground, what is its velocity when it hits the ground ?

Homework Equations


mgΔh=1/2mv2
or
s=vt-1/2at2

The Attempt at a Solution


Using the idea of PE=KE, as the masses cancel out I get an answer of V=7.66ms-1
However I thought that this question can also be done with a suvat equation, I use the same condition which is used for KE [That U=0].

When attempting with suvat I get an answer of 17.15ms-1 why is that ?
 
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CannonSLX said:
When attempting with suvat I get an answer of 17.15ms-1 why is that ?

Hard to tell if you don't show your work!
 
gneill said:
Hard to tell if you don't show your work!
Sorry, I just wanted to know if it was actually possible to be done using suvat ?
 
CannonSLX said:
Sorry, I just wanted to know if it was actually possible to be done using suvat ?
Sure. And the answer should be the same :smile:
 
gneill said:
Sure. And the answer should be the same :smile:
I just tried it again and looked like I forgot how to use my calculator o0), but I did get the same.

Thanks for confirming anyways :)
 
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