Answer:
9 kilojoules of energy are stored in a kilogram of concrete due to sensible heat.
Explanation:
In this exercise we need to determined the sensible heat store in a kilogram of concrete due to a change in temperature. Sensible heat ([tex]Q[/tex]), measured in kilojoules, is defined by the following expression:
[tex]Q = m\cdot c\cdot (T_{f}-T_{o})[/tex] (1)
Where:
[tex]m[/tex] - Mass, measured in kilograms.
[tex]c[/tex] - Average specific heat of concrete, measured in kilojoules per kilogram-degree Celsius.
[tex]T_{o}[/tex], [tex]T_{f}[/tex] - Initial and final temperatures of concrete, measured in degrees Celsius.
If we know that [tex]m = 1\,kg[/tex], [tex]c = 0.9\,\frac{kJ}{kg\cdot ^{\circ}C}[/tex], [tex]T_{o} = 20\,^{\circ}C[/tex] and [tex]T_{f} = 30\,^{\circ}C[/tex], then the energy store in a kilogram of concrete is:
[tex]Q = (1\,kg)\cdot \left(0.9\,\frac{kJ}{kg\cdot ^{\circ}C} \right)\cdot (30\,^{\circ}C-20\,^{\circ}C)[/tex]
[tex]Q = 9\,kJ[/tex]
9 kilojoules of energy are stored in a kilogram of concrete due to sensible heat.
