Molecular Physics | Thermodynamics Answers

Why mercury is used in thermometers but not other liquid???

A person claims that the glass of cold water warmed up to 60°C by gaining the energy from surrounding which is at 25°C. Can this happen?

An engine cylinder has a cross-sectional area of 0.010 m. How much work can be done by a gas
in the cylinder if the gas exerts a constant pressure of 7.5 × 105 Pa on the piston and moves the
piston a distance of 0.040 m?

If I have steel washer in a room at a temperature of 70°F and I move it to a room at 100°F i know it will expand, but will the inside diameter of the washer increase or decrease and why?

Boyle’s law describes the relationship between pressure and volume in a gas
at constant temperature.
i) what is the effect of temperature on volume for a constant
pressure (~50 words) (10 marks)
ii) what is the effect of temperature on pressure for a constant
volume (~50 words) (10 marks)
iii) give two practical examples of the processes mentioned in ii) and iii)
(max 50 words, Hint: in the kitchen and in a car) (5 marks)
please take into account the number of marks for each question

A 2kW kettle, 90% energy efficient is used to boil 1 litre of water from 20°C to 100°C.

i) how long does this take?
ii) how long more to completely boil off the water?

The density of mercury is 13.6grams per centimetres cubed. Find the volume of 2720grams of mercury in centimetres cubed and metres cubed

Boyle’s law describes the relationship between pressure and volume in a gas
at constant temperature.
Can you guess what is the effect of temperature on volume for a constant
pressure (~50 words)(10marks)
ii) Can you guess what is the effect of temperature on pressure for a constant
volume (~50 words)(10marks)
iii) Can you give two practical examples of the processes mentione in ii) and iii)
(max 50 words, Hint: in kitchn&car

A 2 kW kettle, 90% energy efficient is used to boil 1 liter of water from 20ºC to
100ºC. (heat capacity of water is 4180 J/kg.K, latent heat of water is 2256
kJ/kg)
i) How long does this take?(20marks)
ii) How long more to completely boil-off the water(5marks)

A laser delivers pulses of 2mJ at wavelength 633 nm with a pulse duration of
200 ps. (hint E=h.c/l, with h=6.6 x10-34 J.s and c=3x108 m/s and 1 eV=1.6
x10-19 J)
i) How far do they travel in 1s? (5marks)
ii) What is the photon energy in eV?(10marks)
iii) How many photons are delivered per pulse?10 marks)