When a pendulum clock gains time, what adjustiment should be made?

Explanation

To solve the problem of a pendulum clock that gains time, we need to understand the relationship between the pendulum's frequency and its period, as well as how to adjust the pendulum to correct the timekeeping.

### Step-by-Step Solution:

1. **Understand the Problem**:
- A pendulum clock gaining time means it is completing its oscillations faster than it should. This indicates that the frequency of the pendulum's vibrations has increased.

2. **Identify the Formula**:
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