Measuring heat energy
4 marks · NormalA student wants to compare how quickly different materials heat up when supplied with the same energy.
Define specific heat capacity.
Name one property, other than specific heat capacity, that should be kept the same for each material in the comparison.
Explain, using the concept of specific heat capacity, why one material heats up more than another when both are supplied with the same amount of energy.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) The specific heat capacity is the energy needed to raise the temperature of 1 kg of a substance by 1 °C. · must show energy, 1 kg, 1 °C
(b) Mass should be kept the same. · must show mass
(c) A material with a lower specific heat capacity will increase in temperature more than one with a higher specific heat capacity when supplied with the same energy, because less energy is needed for each degree of temperature rise. · must show lower c, higher temp rise, fixed energy
Common mistakes: Confusing mass and specific heat capacity
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States definition of specific heat capacity (energy to raise 1 kg by 1°C).
B2 (b) · 1 mark · Identifies mass as a variable to be kept the same.
B3 (c) · 2 marks · Explains that lower specific heat capacity = higher temperature rise for same energy; links energy, temperature, s.h.c.
Worked solution
a) Specific heat capacity is the amount of energy required to raise the temperature of 1 kg of a substance by 1 °C.
b) The mass of the material should be kept the same.
c) For the same amount of energy, a material with a lower specific heat capacity will be heated more (higher temperature rise) than one with a higher specific heat capacity. This is because it requires less energy for each degree of temperature increase.