Physics Past Questions and Answers

Hot water at a temperature of t is added to twice that amount of water at a temperature of 30°C. If the resulting temperature of the mixture is 50°C. Calculate t.

An air bubble of volume 2 cm\(^3\) is formed 20m under water. What will be its volume when it rises to just below the surface of the water if the atmospheric pressure is equivalent to a height of 10m of water?

The pressure of a given mass of gas changes from 200 Nm² to 100 N m², while its temperature drops from 127^oC to - 73^oC. Calculate the radio of the final volume of the gas to its initial volume.

The temperature of glass vessel containing 100cm3 of mercury is raised from 10^oC to 100^oC. Calculate the apparent cubic expansion of the mercury. (Real cubic expansivity of mercury = 1.82 x 10^-4K^-1) (Cubic expansivity of glass = 2.4 x 10^-5K^-1)

An iron rod of mass 2kg and at a temperature of 280^oC is dropped into some quantity of water initially at a temperature of 30^oC. lf the temperature of the mixture is 70^oC, calculate the mass of the water. (Neglect heat losses to the surroundings). Specific heat capacity of iron = 460 J kg^[/sup]K[sup]) (Specific heat capacity of water = 4200 Jkg ^[/sup]K[sup])