# Pendulum Period change due to gravitational force change

1. Mar 3, 2012

### Sekonda

Hey,

I was wondering how to go about a pendulum problem, basically if we have a clock pendulum that oscillates with period 2s unaffected; if we add a large mass on the floor, so that the pendulum experiences some small extra gravitational force towards the floor.

Now I have determined this force and therefore the extra vertical acceleration due to this added floor mass but I now have to determine how this affects the period.

So provided I know the extra vertical acceleration, how do I determine the effect this has on the period?

Thanks guys!

2. Mar 3, 2012

### LawrenceC

I misread the problem. Comment deleted.

Last edited: Mar 3, 2012
3. Mar 3, 2012

### LawrenceC

The period of a pendulum for small oscillation is

P = 2*pi*sqrt(l/g)

where l is pendulum length and g is acceleration of gravity.

4. Mar 3, 2012

### Sekonda

So based on the fact that the length doesn't change it is safe to assume that period is inversely proportional to the square root of the acceleration and so it's just a case of using the new acceleration and the initial 'g' acceleration to find the difference in the periods.

I think this is most probably the way to go about the problem; though correct me if I'm wrong.

Thanks for the help!
S

5. Mar 3, 2012