A sample of an ideal gas is in a tank of constant volume. The sample gains heat energy and its temperature changes from 300 K to 900 K.

If is the average speed of the gas molecules before absorption of heat and v₂ the average speed after absorption of heat, what is the ratio v₂/v₁ ?

A layer of insulating material with thermal conductivity K is placed on a layer of another material of thermal conductivity 2K. The layers have equal thickness. What is the effective thermal conductivity of the composite sheet?

The reason ocean temperatures do not vary drastically is that:

An ideal gas at STP is first compressed until its volume is half the initial volume, and then it is allowed to expand until its pressure is half the initial pressure. All of this is done while holding the temperature constant. If the initial internal energy of the gas is U, the final internal energy of the gas will be:

Hot water tank of heat capacity 5000 JK⁻¹ contains 10 kg of water at 25 °C. What is the time taken to raise the temperature of the water to 45 °C using a heater coil of power of 3.0 kW, given that the specific heat capacity of water is 4200 Jkg-1 K⁻¹?