If you were to divide the presentday universe into cubes whose sides are 10 million lightyears long, each cube would contain, on
average, about one galaxy similar in size to the Milky Way. Now suppose you travel back in time, to an era when the average distance between galaxies is 0.26 of its current value, corresponding to a cosmological redshift z = 2.7. How many galaxies similar in size to the Milky Way would you expect to find, on average, in cubes of that same size?
Approximately of steam at (assuming that the boiling point of water in this experiment is .)
Explanation:
Latent heat of condensation/evaporation of water: .
Both mass values in this question are given in grams. Hence, convert the specific heat values from this question to .
Specific heat of water: .
Specific heat of copper: .
The temperature of this calorimeter and the of water that it initially contains increased from to . Calculate the amount of energy that would be absorbed:
.
.
Hence, it would take an extra of energy to increase the temperature of the calorimeter and the of water that it initially contains from to .
Assume that it would take grams of steam at ensure that the equilibrium temperature of the system is .
In other words, of steam at would need to release as it condenses (releases latent heat) and cools down to .
Latent heat of condensation from of steam: .
Energy released when that of water from the steam cools down from to :
.
These two parts of energy should add up to . That would be exactly what it would take to raise the temperature of the calorimeter and the water that it initially contains from to .
.
Solve for :
.
Hence, it would take approximately of steam at for the equilibrium temperature of the system to be .