00:01
We have still rails that are being laid, and they are a length of 11 meters.
00:07
And they're laid when the original temperature is negative 2 .5 degrees celsius.
00:14
And we want to know how much space needs to be laid if they are going to expand on a day when the temperature is 35 degrees celsius.
00:24
We have a coefficient of linear expansion to be 1 .2 times 10.
00:30
10 to the negative 5 per degrees celsius, and this is 4 steel specifically.
00:35
And so for a, we're going to use the change in length is equal to the original length times the linear expansion coefficient times change in temperature.
00:45
And again, because we're using change in temperature, we do not need to convert to kelvin.
00:50
And so first, we're going to find the change in length.
00:53
We have original as 11 meters times 1 .2 times 10 to the negative 5 times our change in temperature, which is our final 32 minus 2 .5, which would be 32 plus 2 .5, which gives us 37 .5.
01:09
And so when we find this, we get that it changes 0 .00495 meters.
01:16
And so this is how far apart they need to be laid.
01:20
And if you want to convert this to millimeters to make it a more easier number to look at, it would be 4 .95 millimeters...