00:01
For this question, we are trying to compare the conduction rate through a wall versus that of a window.
00:14
So in order to do that, we want to find the ratio of the two heat conduction rates.
00:20
So let's collect our information first from the problem.
00:24
So i'm going to use the number one for the wall and the number two for the window.
00:40
So the thickness of the window is 13 centimeters, so that's 0 .13 meters, or the wall, rather.
00:51
The thickness of the window is 0 .75 centimeters, which is 0 .0075 meters.
01:01
The area of the wall is 10 square meters, and the area of the window is 2 square meters.
01:14
The thermoconductivity of the wall, we are told, is two times the thermoconductivity of glass wool.
01:24
So if you look that up, this is two times 0 .042 joules per seconds times meters times degrees celsius, which is just 0 .084.
01:42
And it's a glass window.
01:45
So the k for the window, if you look up that of glass, is 0 .84 joules per seconds times meters times degrees celsius.
01:59
The other thing we need is the equation of the rate of heat conduction, which is q equals k times a times t2 minus t1 over the thickness d.
02:13
So since we're going to just look at the ratio, we're also told that the temperature change is the same for the wall in the window.
02:20
So we are going to look at rate of heat conduction of the wall over the rate of heat conduction of the window.
02:30
So on top we have k1, a1, t2 minus t1, over d1, divided by the same thing for the window...