Question about the Conservation of Energy

AI Thread Summary
The discussion centers on the application of the conservation of energy to determine the velocity of a cart rolling down a ramp and flying off a table. The user correctly uses the equation mgh1 = mgh2 + 1/2mv2 but struggles with the height values, initially using h1 as 5 meters and h2 as 3 meters. Clarification is provided that the total height should be considered from the ground level, suggesting h1 should be 8 meters if the table is at 3 meters. The user questions whether the release height can be treated as "0" height, indicating a misunderstanding of reference points in energy calculations. The conversation emphasizes the importance of correctly defining height in energy conservation equations.
nicholz
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If a cart rolled down a ramp 5 meters high and flew off a a table at 3 meters high, what would its velocity be?

please let me know where i go wrong, i was using the law of conservation of energy

mgh1=mgh2+1/2mv2
mg(h1-h2)=1/2mv2
v=square root of 2g(h1-h2)

where h1=5 and h2=3

i plugged in numbers for the variables and i can't seem to get it to work out. is the equation i came up with correct?
edit: i was thinking that it should come out to the square root of 2gh. would that be right though? can i consider the release height to be the "0" height here?
 
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Yes your equation is correct, though since the ramp is 5m high and then the table is 3m high, shouldn't h1=8m?
 

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