- #1

spsch

- 111

- 21

- Homework Statement:
- A charge with mass 1 gram hanging from a pendulum is at equilibrium 12 cm above the lowest vertical position. E= 9500. l the length of the pendulum is 55 cm.

- Relevant Equations:
- QEd = mgh?

Hi, so I was able to solve this problem by just equating the forces (Tension, mg, and EQ).

But I thought I could also solve this problem with Conservation of Energy.

However, I calculated it several times, and I never get the right answer this way.

Doesn't the Electric Field do the work to put this charge at its new Gravitational Potential Energy position 12cm higher?

Or the -difference in Electric Potential is the Gravitational Potential gained?

## Q*E*d = m*g*x ## and therefore ## \frac {mgx}{Ed} = Q ## ?

Or is there another Energy term I am missing?

But I thought I could also solve this problem with Conservation of Energy.

However, I calculated it several times, and I never get the right answer this way.

Doesn't the Electric Field do the work to put this charge at its new Gravitational Potential Energy position 12cm higher?

Or the -difference in Electric Potential is the Gravitational Potential gained?

## Q*E*d = m*g*x ## and therefore ## \frac {mgx}{Ed} = Q ## ?

Or is there another Energy term I am missing?