Question

A simple second pendulum is mounted in a rocket. Its time period will decrease when the rocket is:

• A. moving up with uniform velocity
• B. moving up with uniform acceleration
• C. moving down with uniform acceleration
• D. moving around the earth in geostationary orbit

Answer 1

Answer: (A)

moving up with uniform velocity

Answer 2

The time period of simple pendulum is $T=2\pi \sqrt{\frac{l}{g}}$ $\Rightarrow$ $T\propto \frac{1}{\sqrt{g}}$ Since, time period of second pendulum decreases, so, it implies that effective value of $g$ is increasing. Thus, it means that rocket is accelerating upwards.