Understanding Specific Heat Capacity

 
4.2

 Understanding Specific Heat Capacity

 
  Heat capacity, C  
 

 The quantity of heat energy required to raise the temperature by \(1\,^0\text{C}\).

 
     
 
  Specific heat capacity, c  
 

 The heat energy required to raise the temperature of \(1\text{ kg}\) by \(1\,^0\text{C}\) or \(1\text{ K}\)

 
     
 
  Formula  
  \(Q=mc\Delta\theta\)

 where \(Q\) = energy, \(m\) = mass, \(c\) = specific heat capacity, \(\Delta\theta\) = change in temperature

 
     
 
  •  \(c\uparrow\;\Delta\theta\downarrow\)
     
  • \(c\uparrow\) : heat up slower, cool down slower
  • \(c\downarrow\) : heat up faster, cool down faster
     
  • Mass vs heat content: \(\text{mass}\uparrow\;\text{heat content}\uparrow\)
 
 
Applications of specific heat capacity
  1. Water as cooling agent in car engine
    • water has high specific heat capacity
    • able to absorb more heat without raising its temperature
       
  2. Kitchenware
    • Handle: Higher specific heat capacity, heat up slower
    • Base: Lower specific heat capacity, heat up faster
       
  3. Sea breeze
    • During the day, land heat up faster than sea water (\(c_{land} < c_{sea}\))
    • Warm air rises, lower pressure on land
    • Cooler air flows from sea to land
       
  4. Land breeze
    • During the night, land cool down faster than sea water (\(c_{land} < c_{sea}\))
    • Warm air rises, lower pressure on sea
    • Cooler air flows from land to sea