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Hi there.
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So for this problem, the first part of this problem, ask for the energy necessary to bring one liter of water from a temperature of 20 celsius degrees to 100 celsius degrees.
00:27
Now, to obtain that, we use the equation for the heat that is equal to the energy in this case.
00:38
So the heat is equal to the mass that we want to increase its temperature times the specific heat of the material, which in this case is the specific heat of water, and times the change.
00:59
In temperature.
01:02
Now in here the change in temperature is the final temperature minus the initial temperature.
01:10
Now the final temperature is which we want to obtain is 100 celsius degrees and the initial temperature is 20 celsius degrees.
01:20
So from here we obtain 80 celsius degrees that is the change in the temperature.
01:26
Now for water, well we can obtain the mass first.
01:31
And to obtain the mass, we use the definition of the density, because we know that the density is equal to the mass times the volume, and we are given the volume, and we know the density for water.
01:46
So solving for the mass, we obtained that that is the volume times the density of water.
01:52
Now, we know that the volume that we have is one liter.
02:00
So first, the first thing that we are going to do is to transform one liter to cubic meters.
02:07
So we know that one liter is equal to 1 times 10 to the minus 3 cubic meters.
02:15
So we can eliminate meters.
02:16
So we have this now in cubic meters.
02:19
And now we use the equation and, sorry, the density for water, which is 1 times 10 to the 3 kilograms.
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Per meter per given meter.
02:39
So from here we obtain that the mass of water that we have in here is precisely one kilogram...