# Homework Help: Pendulum clock's period changes as temperature varies

1. Sep 19, 2008

### iTank

1. The problem statement, all variables and given/known data
A pendulum clock is designed to tick off one second on each side-to-side swing of the pendulum (two ticks per complete period).
Will a pendulum clock gain time in hot weather and lose it in cold, or the reverse? Explain your reasoning?

2. Relevant equations
No equation, data, and variables are given, but the question has to do with temperature and heat.

3. The attempt at a solution
I know what the object expands when it's heated, and shrinks when it's cooled. The thermal expansion equation states that (delta)V= B*V0*(delta)T. in words:

change in volume= coefficient * initial volume * change in temperature.

However, i don't think change in volume has anything to do with the period of the pendulum clock. I believe that the mass of the object or the volume of the object all have the same gravitational force (g) pulling towards the center of the earth.

Please help me! this question has been bugging me for days! I can't think of any reasons on how change in volume affects the period of the clock!

2. Sep 19, 2008

### Dick

What's the relation between the length of the pendulum and the temperature. Hot=longer, cold=shorter? Or the reverse? The period of a pendulum is not only related to g, it's also related to the length.

3. Sep 19, 2008

### iTank

Oh i see it now! thanks for helping me out!