The pendulum of a clock is made of a thin iron rod. On a hot day the clock will

Options

A. run fast
B. runs slow
C. give accurate time
D. not work

Answer

**Step-by-Step Solution:**

1. **Understanding the Pendulum**: The pendulum of a clock is typically made of a material that can expand or contract with temperature changes. In this case, the pendulum is made of a thin iron rod.

2. **Effect of Temperature on Length**: When the temperature increases (on a hot day), the iron rod will expand. This expansion results in an increase in the length of the pendulum.

3. **Relationship Between Length and Time Period**: The time period (T) of a simple pendulum is given by the formula:
\[ T = 2\pi \sqrt{\frac{L}{g}} \]
where \(L\) is the length of the pendulum and \(g\) is the acceleration due to gravity. From this formula, we can see that the time period is directly proportional to the square root of the length of the pendulum.

4. **Impact of Increased Length**: Since the length \(L\) of the pendulum increases due to thermal expansion, the time period \(T\) will also increase. This means that it will take longer for the pendulum to complete one full swing.

5. **Conclusion on Clock Performance**: As the time period increases, the clock will take more time to complete each cycle. Therefore, the clock will run slower on a hot day.

**Final Answer**: On a hot day, the clock will slow down.

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