1995 - WAEC Physics Past Questions and Answers - page 2
A mercury-in-glass thermometer reads - 20o at the ice point and 100o at the steam point. Calculate the celcius temperature corresponding to 70o on the thermometer.
A brass rod is 2 m long at a certain temperature. Calculate the linear expansion of the rod for a temperature change of 100K. (Take the linear expansivity of brass as 1.8 x 10'5K").
A body of specific heat capacity 450J kg-1 K-1 falls to the ground from rest through a vertical height of 20m. Assuming conservation of energy, calculate the change in temperature of the body on striking the ground level. (g = 10ms-2)
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* is formed 20 m 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 10 m of water?
The pressure of a given mass of gas changes from 200 Nm2 to 100 N m2, while its temperature drops from 127oC to - 73oC. 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 10oC to 100oC. 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 280oC is dropped into some quantity of water initially at a temperature of 30oC. lf the temperature of the mixture is 70oC, calculate the mass of the water. (Neglect heat losses to the surroundings). Specific heat capacity of iron = 460 J kgK) (Specific heat capacity of water = 4200 Jkg K)
How much heat is required to convert 20 g of ice at 0oC to water at the same temperature? (Specific latent heat of ice = 336 J g-1)
When two objects P and Q are supplied with the same quantity of heat, the temperature change in P is observed to be twice that in Q. lf the masses of P and Q are the same, calculate the ratio of the specific heat capacities of Q to P.