I know that the relationship between altitude and atmospheric density is that the higher the altitude, the lesser the density, and the lower the altitude the higher the density. Lower density float to the top, and higher density is 'heavy' so it comes down
Yes.
In fact, from the graph we see that the threshold frequency (the minimum energy of the incoming energy needed to extract a photoelectron from the material) is
(we see it because this is the frequency at which the maximum kinetic energy of the emitted electron is zero).
The incoming photon in this problem has a frequency of 8.0 E14 Hz, so above the threshold frequency, therefore it is enough to extract photoelectrons from the material.
Answer: The total rate of heat transfer from the container to its surroundings ignoring radiation is 332.67 W.
Explanation:
Given: Inner diameter = 0.9 m
q = 872 
Now, radii is calculated as follows.

Hence, the rate of heat transfer is as follows.

where,
V = volume of sphere = 
Substitute the values into above formula as follows.

Thus, we can conclude that the total rate of heat transfer from the container to its surroundings ignoring radiation is 332.67 W.
The work is 90 as 5 times 18