00:01
All right, so let's see we have a spherical balloon that has blown up that has a radius of 0 .25 meters.
00:09
And the pressure inside the balloon is 1 .25 atmospheres.
00:15
And the temperature right in kelvin, it's going to be 295 kelvin.
00:23
So we want to figure out if it's filled with nitrogen gas, what is the mass of a single into molecule? so we don't need anything about the balloon to figure this out.
00:32
But this m is going to be like the molar mass divided by avagadra's number.
00:38
So this is 0 .08 kilograms divided by 6 .022 times 10 to the 23rd.
00:49
And so 028 divided by 6 .6 .022 times to the 23rd.
00:55
This should be about 4 .65 times 10 to the negative 26 kilograms.
01:02
Part b asks, how much translational kinetic energy does an average molecule have in this gas? so we can write this as one -half mv squared, right? this is our kinetic energy.
01:16
And the speed is going to be like the rms speed.
01:19
So this is one -half times m times 3kt over m.
01:26
And so if you look at this, this is just going to be three -half k -t, or t is our temperature...