Assume that a room at sea level was filled with a gas of oxygen molecules O2 in thermal equilibrium at 0 °C. There are 8 protons and 8 neutrons in the nucleus of an oxygen atom O. You may take the masses of the proton and the neutron to be the same, and ignore the mass of the electrons. 1 atm=1.01х105 N/m2 , ℏ=1.05х10-34 J·s , mp=1.67х10-27 kg.
a) What would the (particle) number density be according to the ideal gas law?
b) Compare the number density with the quantum concentration at the same temperature.
c) Is the gas in the classical or quantum regime?

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)

An charge with mass m and charge q is emitted from the origin, (x,y)=(0,0). a large, flat screen is located at x=l. there is a target on the screen at y position y(h), where y(h) > 0. in this problem, you will examine two different ways that the charge might hit the target. ignore gravity in this problem. 1.assume that the charge is emitted with velocity v(0) in the positive x direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive y direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l. 2.now assume that the charge is emitted with velocity v(0) in the positive y direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive x direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l.