# General information about a Pendulum

1. Apr 26, 2005

### squib

More Physics.... A simple pendulum suspended in a rocket ship has a period T0. Assume that the rocket ship is near the earth in a uniform gravitational field. Give ALL correct answers,
I'm assuming T= 2pi(l/g)^.5

A) If the ship moves upward with a constant velocity, the period increases.

velocity has nothing to do with l or g, so no change, so FALSE

B) If the ship accelerates upward, the period decreases.

This will cause a smaller g, and thus INCREASE the period, so FALSE

C) If the mass of the pendulum doubles, the period increases.

MASS is not considered here, so no change, so FALSE

D) If the ship accelerates downward at 9.8 m/s2, the pendulum will oscillate faster.

G will increase here, so the period will be smaller, and thus oscillate faster, so TRUE.

E) If the length of the pendulum is doubled, the new period will be: the square root of two times T0.
This seems true by the formula too... TRUE

Yet DE is not right. I even tried ADE in case a constant velocity outward (A) meant the force of gravity would lessen... but still no luck.
Any help here?

2. Apr 26, 2005

### OlderDan

You need to rethink this one. After you understand this, go on to the later ones.

3. Apr 26, 2005

### krab

Have you been in an elevator? Remember that when it begins moving upward you feel momentarily heavier? So g increases.

4. Apr 26, 2005

### squib

Haha, wow, super stupid mistake there by me. Thanks