An elevator initially accelerates upward from rest and then ascends with uniform speed. The time period of a simple pendulum in the elevator will:
Correct answer: B. Decrease and then increase
- A. Increase and then decrease
- B. Decrease and then increase
- C. Increase
- D. Decrease
Explanation
In an elevator that initially accelerates upward from rest and then ascends with uniform speed, the effective gravitational force experienced by the simple pendulum inside the elevator will change. During the initial acceleration, the effective gravitational force will be greater than g. As a result, the time period of the simple pendulum will be shorter because the effective acceleration acting on the pendulum is greater. Once the elevator reaches a constant speed, the effective gravitational force will return to g, and the time period of the simple pendulum will return to its original value. Hence B is the correct option.
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