Question

How much heat energy, in joules, is released to your body after you drink a cup of hot tea containing 125g of water that is cooled from 55℃ to a body temperature at 37℃ (water has a specific heat capacity of 4.184 J/g℃

Answer 1

Answer:

$Q_{out} = 9414\,J$

Explanation:

The heat release to the human body is determined with the help of the First Law of Thermodynamics:

$-Q_{out} + U_{in} - U_{out} = 0$

$Q_{out} = U_{out} - U_{in}$

$Q_{out} = m\cdot c_{w}\cdot \Delta T$

$Q_{out} = (125\,g)\cdot \left(4.184\,\frac{J}{g\cdot ^{\textdegree}C} \right)\cdot (55^{\circ}C - 37^{\circ}C)$

$Q_{out} = 9414\,J$

Answer 2

Answer:

$Q=-9414J$

Explanation:

Hello,

In this case, the released heat by the water in this heating process is defined in terms of its mass, heat capacity and temperature difference as shown below:

$Q=mCp\Delta T$

Thus, with the given data indicating that water was at 55 °C before entering the body, we obtain:

$Q=125g*4.184\frac{J}{g^oC}*(37-55)^oC$

$Q=-9414J$

Such negative result means that the water releases that amount of heat to the body.

Best regards.