paulb203
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- TL;DR Summary
- Trying to grasp the basics
I’m working my way through Khan Academy’s High School Physics and I want to check that I’m getting the concept of conservation of energy. Is the following at least roughly correct?
When a ball is rolled down a U-shaped ramp from the top of one side it will, ignoring friction, travel to the bottom of the ramp, up the other side to the top, back down , and up the first side to where it began, etc, etc, ad infinitum.
The U is converted to K as the ball descends, and the K is converted to U as it ascends.
At the respective tops the U ‘tank’ is full. At the bottom it is empty.
At the tops the K ‘tank’ is empty. At the bottom it is full.
Halfway down, or up, both tanks are half full.
**
When rolling it down, and taking friction into account, it won’t get quite to the top of the other side as some of K will be converted to thermal energy and sound energy. It will get part the way up the other side, to position h, descend, and then part the way up the first side, but not as far as h, etc.
The total energy at the outset = the total energy once the ball has come to rest at the bottom of the ramp. If there was x Joules of U(GPE) at the beginning there is x Joules of energy now, but in different forms.
When a ball is rolled down a U-shaped ramp from the top of one side it will, ignoring friction, travel to the bottom of the ramp, up the other side to the top, back down , and up the first side to where it began, etc, etc, ad infinitum.
The U is converted to K as the ball descends, and the K is converted to U as it ascends.
At the respective tops the U ‘tank’ is full. At the bottom it is empty.
At the tops the K ‘tank’ is empty. At the bottom it is full.
Halfway down, or up, both tanks are half full.
**
When rolling it down, and taking friction into account, it won’t get quite to the top of the other side as some of K will be converted to thermal energy and sound energy. It will get part the way up the other side, to position h, descend, and then part the way up the first side, but not as far as h, etc.
The total energy at the outset = the total energy once the ball has come to rest at the bottom of the ramp. If there was x Joules of U(GPE) at the beginning there is x Joules of energy now, but in different forms.