016 (part 1 of 2) 10.0 pointsA window has a glass surface of 4007 cm2 and a thickness of 3.1 mm_ Find the rate of energy transfer by conduc- tion through this pane ...

A thermopane window consists of two glass panes, each $0.50 \mathrm{~cm}$ thick, with a $1.0$ -cm-thick sealed layer of air in between. If the inside surface temperature is $23^{\circ} \mathrm{C}$ and the outside surface temperature is $0.0^{\circ} \mathrm{C}_{?}$ determine the rate of energy uransfer through $1.0 \mathrm{~m}^{2}$ of the window. Compare your answer with the rate of energy transfer through $1.0 \mathrm{~m}^{2}$ of a single $1.0-\mathrm{cm}$ -thick pane of glass.

Hi and this question forgiven that the temperature difference between the inside and outside attempt outside of glass window is 20 degrees socials and the window is 110 centimetres by 100 centimeters by 10 millimeters. So $10 million is a thickness which is this L The area is 100 times wondering sentiment us which will be one m by one m and one that will be equal to one m squared. And we're giving d come on conductivity as Your .851 to find how much energy passes street wind three class in one second. So the time is one second and you will find in the Tokyo to the T. We want to go to the cure equal to almost playing this, they said Subsequuting have zero x 8, five times one times 20 over 10 times stands of -3 times when digital culture and is equal to 1700 jewels, which is 1.7 Killer Jaws. That is our answer.

Consider a firm It'll Window, which is comprised of two layers of class space air between it as cross sectional area of 6.0 square meters and the two layers of glass. He's going to be a fitness four millimeters. I'm gonna label that else of G for thickness of glass of 4.0 millimeters or 0.400 meters. Always want to switch things back to s. I mean, it's so that they're compatible for when we need calculate stuff and the gap of air else of a is five millimeters so zero 0.0 500 meters and the temperature inside T's of hot is 20.0 degrees Celsius and the temperature outside T succeed. He's cold is negative 30.0 degrees Celsius, and we want to figure out what the rate of energy transfer by conduction through the window is. So first we're going to just go ahead and use Equation 20.17 which is our nice, uh, restructuring law, thermal conduction for GIs, additive slams of things to get through. So that's giving us as the power is given by the cross sectional area times the hot temperature, my school temperature Delta t over the some of the lengths over their relative for Malakand activities Ground label that Okay. And we can go ahead and try and expand this for ourselves. I'm gonna scroll little. So for us, our power is gonna be able to the let's start with the bottom. We have the out length of the air gap over the formal conductivity of the air gap plus two because there's two glass barriers to times the length of the glass over V from a conductive ity of the glass. Now, for numerator, it's just again our cross sectional area Times are hot, temperature minus are cold temperature. So what? We know everything here except for these formal conductivity ease which we have to go get from table 20.3 and you can see that the K for glass is gonna be 0.8 and these air in lots per meter degree Celsius and the formal conductivity of the air is going to be 0.2 free four watts, her Peter degrees Celsius. So, as you would expect the air so much worse from a conductor than the glass. So let's go and just plug this all into a final equation so we can go ahead and evaluated. So our power again is going to be given by I'm just gonna go ahead and expand all this. It's gonna be 6.0 meters squared as a cross sectional area and then 20.0 degrees Celsius minus negative, 30.0 degrees Celsius. Uh, prophecy there, too. And that's over. Just our lengths over beginning our formal connected these 0.500 meters over 0.2 free four watts per meter degree Celsius. That's our air component and then two of our glass components. But you're only four millimeters thick and have the formal conductive ity of 0.8 wants her meter degree Celsius, and you can plug all that into whatever your preferred calculation that it is to get 1.34 kilowatts. We're maintaining the three significant figures that we've been given from all the data that we have, and that's it. That is the rate of energy transferred by conduction through our formal insulated window

In this problem were given the area off heat window is equal toe. Six point of 0 m were on. The difference in the temperature is 50 degrees. Interviewed. There are two years off the glass and sorry. They're two layers of glass and the thickness off each layer off glass is equal to four millimeter, which is equal toe for multiple away. Think about ministry meter, and there is a layer of air between these two layers off glass. So the thickness off here he's given is five millimeter, which can replace five multiple. I think about minus three later. We have to find the rate of Mary transfer in the formula to find the definite transfer in this case is Goto Delta T into area divided by to into thickness of glass, divided by Kate for glass. Less thickness Affair divided by care for air Well subdued develops in this equation. Now there to get veritas next transfer so that definitely transfer is equal to Delta. T is 50 degrees interviewed. Multiply by area is 6.0 m square. This whole divided by we will succeed the value off to into thickness off glasses four multiplied by thank you. Power minus 3 m, divided by the cave for glasses. 0.8 0.8. Work for me to party disintegrated. Less thickness off. You make life record thickness off the areas. Five multiple er I thank you. Power minus 3 m, divided by care for it is 0.234 Ward permitted birdie disintegrate when we saw this figured direct atthe energy transfer is equal to 1.34 kilowatt, which is the answer of the question.

What a healthy given problem. The rate of energy transfer through a compound slave he's given by P is equal to eight times delta t change in temperature divided by our where are are is ah, some off the lens derided by K I isa conductive ity. So, um, for a tar Maupin Olle equal to our off the band man plus our off a tramp there dripped here plus are off the pain So this is a cult to our most depend Plus are off the trip there food here Then we can find our biceps treating the values two times 0.5 old times 10 to the power minus two plus one times 10 to the power minus two divided by Here's a 0.8 And here derided bison report 0 to 3 This gives us the car will you 0.44 meter square degree Celsius. I won't from here. Then we can find a p so p will be one meter square Because I was there a 0.44 terms Temperature differences 23 D Excuse us 50 to watch I got to be For once, Adam, it'll take paying off a last live. We have our physical to one time center. Power minus two, divided by 0.8. This gives us one done Shit over. Um, minus two meter meter. Squared off. Ah, Celsius forward. So street value for our in power equation, That is one time screw to three. You're right by 10 to the power minus two. Excuse us two times 10 to the power three watch, which is equal to two kilowatts. So which is a 38 times greater than greater than, uh, greater than when there is an air between the last lips.