Hey folks I been going through past exam papers and got 4 questions which are hard to follow, for those that know please provide a detailed step by step guide. I have completed most of the previous parts of each question which got me some extra values.(adsbygoogle = window.adsbygoogle || []).push({});

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Question 1

OK heres what I have worked out so far:

Volume = 5*10^-3

Mass = 8*10^-3

Pressure = 900000

n = 2

molecular mass = 4

r.m.s Speed of all molecules = 1300

Question asks the r.m.s speed of all molecules when the Kelvin temperature has doubled. All I know is that speed is proportional to temperature.

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Question 2

Should be quick and simple

Use an ideal gas equation and kinetic theory formula pV = (1/3)Nmc^2 to show the equivalant formula is U = N * (1/2)mc^2

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Question 3

Pressure = 1.5*10^16

Density = 1.8*10^5

r.m.s Speed = 500000

Number of protons per m^3 = density/proton mass = 1.08*10^32

Question asks me to calculate the number of moles per m^3 and then the temperature.

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Question 4

Concerning a water radiator

Metal sheet dimensions = 0.9*1.5*0.005m

Solar Radiation arrives at 350W

Water pumped at (0.45/60)W

Temp' Difference = 26 - 15 degs = 11 degs

Mass of water = 1kg

Heat Capacity = 4200

Calculate the percentage of solar energy transferred to water.

Then, using the formula Q/t = -kA(temp diff/x)

Make a rough estimate of the temperature difference between top surface and bottom of aluminium sheet.

Any help would be great!

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# Homework Help: A-Lev Physics Gas and Thermal?

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