High School Conservation of Energy: Ball on a U-Shaped Ramp

[paulb203]

TL;DR

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.

 

[erobz]

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.

Yeah, when you introduce friction you add some more “internal energy tanks” for the system and its surroundings i.e. the mass in the ball can change temperature, or the mass in the space around the ball can change temp, sound, light, and maybe some exotic things I don’t think/know about. These new tanks don’t share with potential and kinetic energy tanks without additional work, but they will share with each other. “Heat” ( the flow of thermal energy) will occur between the system and its surroundings.

 

[Dullard]

You got it.