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MAT7 homework help

Added Feb 19, 2020 •

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okay this is homework help with Matt 6 which involves linear expansion problems these are the problems that are on the back of the of the sheet the front side of course do a little reading in the book it some equations down here that are useful at the bottom and then we're going to start using those here so is he a piece of aluminum house siding is 3.66 M long and let's see cold winter day of -28 degrees Celsius so that's our first temperature or low temperature I'll call it T1 how much longer is it on a very hot summer day of 39° Celsius so our second temperature is going to be 39 degrees Celsius this is really really hot this is probably about a hundred and ten degrees and this is really cold this is like 40 50 below some so we're getting to use some real a place where we have a very very temperate climate the Barbarian on temperate climate climate that changes a lot the last thing we need to know is what Alpha 4 aluminum is so we can look that up here page 914 the text has it listed for 10 x 25 x 10 to the negative 6 it's not worried about the units for Alpha so now it's going to be a matter of finding out how much longer is it that's Delta L that equal to elf x l One X delta-t it looks like we need to find delta T so we'll use T1 and T2 to find delta T or change so that's going to be 39 - -1 date so that gives us a change of temperature of 67 degrees Celsius so looks like you got everything for the first one so listen to the second one and see what's going on a piece of steel is 11.5 cm long so our initial length is 11.5 CM we're going to need to convert that from centimeters to meters there's 100 cm in 1 meter the meters and the initial temperature is 22 degrees Celsius is heated to a second temperature of 1221 degrees Celsius so you'll subtract these two to find delta T now how long is it and we're given Alpha for steel is 12 x 10 to the negative 6 okay so first of all after you find Delta l by using Delta L is equal to Alpha L1 delta-t the next thing that you're going to do is after you find Delta L to find the new length will call it  to our piece of Steel what we do is we add L1 and the change together and that'll give you your new one so first of all find Delta L don't forget to subtract the temperatures to get delta-t first find out the Ellen and add that to the original length the number 91 this is called number 91 cuz it's out of the textbook a bar of unknown metal so it's unknown metal or trying to identify the metal has a length of so it's like initial length is zero Point 975 M at 45 degrees Celsius and this is actually L2 and this is temperature to use of a higher temperature wants so when I read further it says and a length of 2.972 M so length one is 0.972 M and that was at a temperature T1 of 23 degrees Celsius so let's see if we can find Delta Elmo on this one by doing L 2 - L1 so we can find Delta L now the change of lay by taking the length at the higher temperature and subtracting the length of a lower temperature I can get like .00 3 meters and then we can find delta T that's subtracting the 45 and 23 now the last thing that we need Lexi we know Delta L we Noel one so if we look at this equation Delta l equals Alpha L1 Delta Chi we know what the  is weed subtract them we know what L one is that's this we know it delta-t is we subtract the two teas to do that and we want to find Alpha so I'm going to rearrange this is Delta L / L1 Delta Chi bring the L1 in the delta T to The Other Side by dividing so you'll use this equation to call this problem how much longer will a 300M Steel Bridge be on a 30 degrees C day than a point that I -10 degrees Celsius night where it's a Steel Bridge so 12 x 10 to the is 6 is our Alpha so our initial length is 300M we have a low temperature of -10 degrees Celsius make sure you pay attention to the negative we have our second 30° Celsius to it's not 20° difference in temperature more than that and are Elfa is 12 x 10 to the negative 6 so you want to know how much longer will it be that still 2L to find l2l you need Alpha L1 and delta-t those him those pieces of information Elfa L1 and L2 teak and I'll be found so good luck solving that one the last one what is the change in length or trying to find Delta L again I think I supposed to eat a copper pipe call a couple spelling errors I'm copying it from the book so our initial length is 2.00 meters is copper pipe so let's see copper we can look that one up copper in the state of table is 17 time 10 to the negative 6th that's copper so I know what Elsa is Elsa is 17 x 10 to the negative 6 I know that the initial temperature to you want is 23° C 72 is 978 degrees Celsius so we would subtract those to find our delta-t and this was supposed to be this word over yours would be from not form so cut a spelling error sorry about that now the thing I need to find Delta l r Alpha L1 and delta-t you can find those things and find how much longer this copper pipe will be okay good luck

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