High School

At a depth of \(x\) metres, the temperature of the water in an ocean is \(T^{\circ} C\). At depths below 900 metres, \(T\) is inversely proportional to \(x\).



\(T\) is given by:



\[ T = \frac{4500}{x} \]



(a) Calculate the difference in the temperature of the water at a depth of 1200 metres and the temperature of the water at a depth of 2500 metres.

Answer :

- Calculate the temperature at 1200m: $T_1 = \frac{4500}{1200} = 3.75^{\circ}C$.
- Calculate the temperature at 2500m: $T_2 = \frac{4500}{2500} = 1.8^{\circ}C$.
- Find the difference in temperature: $|T_1 - T_2| = |3.75 - 1.8| = 1.95^{\circ}C$.
- The difference in temperature is $\boxed{1.95^{\circ}C}$.

### Explanation
1. Understanding the Problem
We are given that the temperature $T$ at a depth $x$ is given by $T = \frac{4500}{x}$. We need to find the difference in temperature at depths of 1200 metres and 2500 metres.

2. Calculating Temperature at 1200m
First, let's calculate the temperature at a depth of 1200 metres. We have $T_1 = \frac{4500}{1200}$. The result of this calculation is $T_1 = 3.75^{\circ}C$.

3. Calculating Temperature at 2500m
Next, let's calculate the temperature at a depth of 2500 metres. We have $T_2 = \frac{4500}{2500}$. The result of this calculation is $T_2 = 1.8^{\circ}C$.

4. Finding the Difference in Temperature
Now, we need to find the difference in temperature, which is $|T_1 - T_2| = |3.75 - 1.8|$. The result of this calculation is $1.95^{\circ}C$.

5. Final Answer
Therefore, the difference in the temperature of the water at a depth of 1200 metres and the temperature of the water at a depth of 2500 metres is $1.95^{\circ}C$.

### Examples
Understanding how temperature changes with depth is crucial in oceanography. For example, marine biologists use this information to study the distribution of marine life, as different species thrive at different temperatures. Similarly, engineers designing underwater pipelines or cables need to account for temperature variations to ensure the materials can withstand the conditions. This principle of inverse proportionality helps predict and manage various aspects of ocean environments.