Question

If the temperature difference between the body and surroundings is small, then the rate of loss of heat is directly proportional to _______.

Answer 1

Definition of Heat

1. Heat is a form of energy that will be transferred from one person's body to another person's body which results in a difference in temperature.
2. Suppose two bodies at dissimilar temperatures are brought in touch, and then energy is transferred (i.e., heat flows from the hotter body person to the colder body).

Rate of loss of Heat

The rate of heat loss may be mathematically expressed as $=-\frac{dQ}{dt}$.

Where, $dQ$ is heat loss and $dt$ is with respect to time, the negative sign indicates loss of heat.

Newton's law of cooling:

This is directly proportional to the current temperature difference between the two bodies and their surroundings. i.e.,

$-\frac{dQ}{dt}\propto ∆T$

Where, $△T=T_2-T_1$

Where, $T_{1}and{T}_2$ are the temperature of the two bodies. $∆T$ is the difference in their temperature.

1. This statement is Newton's law of cooling where the rate of loss of heat is directly proportional to the temperature difference between the body and the surroundings.
2. When hot water is left on a table, it cools gradually. It reaches the temperature of the environment.
3. The hot water can cool down by exchanging heat with the surroundings. Here, the cooling of hot water depends upon the difference between its temperature and the environment.
4. A hot body loses its heat to its surroundings in the form of radiation. The rate at which loss of heat occurred depends on the difference in temperature between the body and its surroundings.

Thus, if the temperature difference between the body and surroundings is small, then the rate of loss of heat is directly proportional to the difference between the temperature of the two bodies.