A boulder of mass 600kg tumbles down a montainside and stops 160 m below. If the temperature of the boulder, montain, and surrounding air are all at 300k, What is the change in entropy of the Universe? I
I know the formula but I dono what I have to do with the given mass? How do I find Q?
2007-01-17 14:00:53 · 1 answers · asked by Kitana 2 in Science & Mathematics ➔ Physics
Entropy units... Joules per Kelvin
The potential energy was at some value before the boulder fell. As the boulder fell, it gained Kinetic Energy. Well, because the boulder stopped, it had to give up its energy causing a change in entropy.
We know how much the potential energy change was because it fell 160m. PE=mgz MassXGravityXHeight. Multiple these together you get Energy, or 940800 Joules... also known as Q. Q/T = 640800/300=3136J/K
So 3136J/K
2007-01-17 15:08:18 · answer #1 · answered by Dangermouse! 2 · 1⤊ 0⤋