Specific heat and heat capacity – problems and solutions

1. A body with mass 2 kg absorbs heat 100 calories when its temperature raises from 20oC to 70oC. What is the specific heat of the body?

Known :

Mass (m) = 2 kg = 2000 gr

Heat (Q) = 100 cal

The change in temperature (ΔT) = 70oC – 20oC = 50oC

Wanted : The specific heat (c)

Solution :

c = Q / m ΔT

c = 100 cal / (2000 gr)(50oC)

c = 100 cal / 100,000 gr oC

c = 102 cal / 105 gr oC

c = (102 cal)(10-5 gr-1 oC-1)

c = 10-3 cal gr-1 oC-1

c = 10-3 cal/gr oC

The specific heat of the body is 10-3 cal/gr oC

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2. The specific heat of water is 4180 J/kg Co. How much the heat capacity of 2 kg water…

Known :

The specific heat (c) = 4180 J/kg Co

Mass (m) = 2 kg

Wanted : Heat capacity (C)

Solution :

C = m c

C = (2 kg)(4180 J/kg Co)

C = (2)(4180 J/Co)

C = 8360 J/Co

3. The specific heat of aluminum is 900 J/kg Co. How much the heat capacity of 2 gram aluminum…..

Known :

The specific heat of aluminum (c) = 900 J/kg Co = 9 x 102 J/kg Co

Mass (m) = 2 gram = 2/1000 kg = 2/103 kg = 2 x 10-3 kg

Wanted : Heat capacity (C)

Solution :

C = m c

C = (2 x 10-3 kg)(9 x 102 J/kg Co)

C = 18 x 10-3 x 102 J/Co

C = 18 x 10-1 J/Co

C = 1.8 J/Co

  1. Converting temperature scales
  2. Linear expansion
  3. Area expansion
  4. Volume expansion
  5. Heat
  6. Mechanical equivalent of heat
  7. Specific heat and heat capacity
  8. Latent heat, heat of fusion, heat of vaporization
  9. Energy conservation for heat transfer