Question

The cooling curve of a hot body is a graph of temperature T versus time t. What is the correct description of this curve?

Options

• A straight line with a negative slope

• A straight line with a positive slope

• An exponential decay curve, steep initially, then gradually flattens

• A parabola opening downward

Answer 1

An exponential decay curve, steep initially, then gradually flattens

Explanation:

Since the rate of cooling decreases as the body approaches room temperature, the T vs t graph drops steeply at first and then progressively flattens out. This shape reflects the exponential nature of Newton's Law of Cooling, the body cools rapidly when the temperature difference is large and slowly when it is small.