WEBVTT 00:00.080 --> 00:02.910 This is Giancoli Answers with Mr. Dychko. 00:03.980 --> 00:06.630 First we'll calculate the amount of energy absorbed by the soup, 00:06.630 --> 00:11.190 and that's 250 milliliters is 0.25 liters, 00:11.190 --> 00:13.830 and times by the density of water, 1 kilogram per liter, 00:13.830 --> 00:17.530 to get the mass, that together that makes the mass. 00:17.530 --> 00:21.470 And then times by 4,186 joules per kilogram Celsius degree 00:21.470 --> 00:23.710 in that specific heat capacity of water 00:23.710 --> 00:25.340 and then times by the change in temperature, 00:25.340 --> 00:29.210 final temperature of 75 degrees Celsius minus the initial temperature of 15. 00:29.210 --> 00:35.430 And you get 62,790 joules of energy need to be gained by the soup. 00:35.430 --> 00:38.810 So, power is energy divided by time, 00:38.810 --> 00:42.110 energy in this case is Q. 00:42.110 --> 00:43.870 And then we'll solve for t 00:43.870 --> 00:46.590 by multiplying both sides by t over p. 00:46.590 --> 00:47.990 So, on the left side were left with t, 00:47.990 --> 00:50.140 on the right side we're left with a Q over p. 00:50.140 --> 00:53.990 So, energy gained is heat divided by power. 00:53.990 --> 01:02.490 So, that's, 62,790 joules divided by 375 watts 01:02.490 --> 01:04.750 but watts are joules per second. 01:04.760 --> 01:08.250 And in this gives about 170 seconds.