THERMODYNAMICS AND STATISTICAL PHYSICS 7The vapor pressure at this temperature is and the total mass
of the astronaut4.7 Grand Lunar Canals (Moscow Phys-Tech)
In one of his novels, H. G. Wells describes an encounter of amateur earthling
astronauts with a lunar civilization living in very deep caverns beneath the
surface of the Moon. The caverns are connected to the surface by long
channels filled with air. The channel is dug between points A and B on
the surface of the Moon so that the angle (see Figure P.4.7).
Assume that the air pressure in the middle of a channel is atm.
Estimate the air pressure in the channel near the surface of the Moon. The
radius of the Moon The acceleration due to gravity on the
surface of the Moon where is theacceleration due togravity
on the surface of theEarth.4.8 Frozen Solid (Moscow Phys-Tech)
Estimate how long it will take for a small pond of average depth m
to freeze completely in a very cold winter, when the temperature is al-
ways below the freezing point of water (see Figure P.4.8).Take the ther-
mal conductivity of ice to be the latent heat of fusion