4 ms·
> Thus, by lifting the weight, the magic material would be doing work, and expending energy. But where does it get the energy from? From the pull of gravity on
by gnaritas 14y ago
> Thus, by lifting the weight, the magic material would be doing work, and expending energy. But where does it get the energy from?
From the pull of gravity on the weight.
- caf 14y ago"The pull of gravity" is not a source of energy. When the weight rises in the Earth's gravitational field energy must be supplied.
- gnaritas 14y agoThinking about it more, yea, fair point. When water loses energy and freezes, it expands, that expansion could lift a weight. Is this not a similar change in molecular structure doing a similar thing? Where is the input of energy lifting this weight.
- toemetoch 14y agoNo. When you apply pressure on ice it becomes liquid. In other words: water doesn't lift things by freezing if that requires an amount of energy larger than what is needed to change state.
- deleted 14y ago[deleted]