How Do Gravitational Potential and Kinetic Energy Relate in Energy Conservation?

AI Thread Summary
Gravitational potential energy (PE) is calculated using the equation PE = mgh, while kinetic energy (KE) is given by KE = 1/2mv². The discussion highlights a confusion regarding the relationship between mass and speed, noting that less mass does not necessarily equate to higher speed. Key to understanding energy conservation is recognizing that at the point of transition, potential energy equals kinetic energy, leading to the equation mgh = 1/2mv². This reveals that mass cancels out, indicating that the speed of an object depends on the height from which it falls, not its mass.
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Homework Statement

box.jpg

Homework Equations


Wgravity = mgh
KE=1/2mv2

The Attempt at a Solution



I know the gravitational potential energy is different because mgh accounts for mass.
But the book says that B is correct. I don't know why because isn't the less mass you have the faster you go? 2KE/m=v2
 
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okgo said:

Homework Equations


Wgravity = mgh
KE=1/2mv2

The Attempt at a Solution



I know the gravitational potential energy is different because mgh accounts for mass.
But the book says that B is correct. I don't know why because isn't the less mass you have the faster you go? 2KE/m=v2

Step back a bit and look at the equations.

PE = KE at the bottom.

m*g*h = 1/2*m*v2

v2 = 2*g*h

The mass has canceled out.
 

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