As morning sunlight falls on a tethered helium balloon, it expands from a volume of 1.10 cross 103 m3 to a volume of 1.17 cross 103 m3.
If the initial temperature of the helium is 270 K, how much does the helium's internal energy increase?
Again, if the initial temperature of the helium is 270 K, how many joules of solar energy are absorbed?