Measurement of thermal energy questions | form three Physics

Define:
(i) Heat Capacity
(ii) Specific Heat Capacity

Answer / Solution

UNSOLVED

A specific latent heat of fusion of a substance is defined as energy required to
A change a unit mass of the substance from solid to liquid.
B change a unit mass of a substance from solid to liquid at constant temperature.
C change the mass of a substance from solid to liquid at constant temperature.
D cause a unit temperature rise of a substance.
E cause a unit mass of water to freeze at 0°C.

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UNSOLVED

(a) What is meant by the terms heat capacity and specific heat capacity? State how they are related.
(b) Explain briefly how heat losses have been prevented in a vacuum flask.
(c) A heater of 500W is used to raise the temperature of 50 kg of material of specific heat capacity of 960J/kg K, from 18°C to 38°C. Assume that all of the heat from the heater is given to the material. Calculate:
(i) heat capacity of the material
(ii) the time taken in seconds.

Answer / Solution

UNSOLVED

A lump of copper of mass 0.5 kg is placed in an oven for some time then quickly transferred to a large dry block of ice at 0°C forming 0.3kg of ice after a short period.
(i) Estimate the temperature of the oven.
(ii) Give two reasons why the estimated temperature in (i) above might be lower than the actual temperature of the oven?

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UNSOLVED

(i) What is meant by specific latent heat of vaporization.
(ii) Name two factors which affect the boiling point and freezing point of water.

Answer / Solution

UNSOLVED