A parallel-plate capacitor with plate area 2.6 cm^2 and air-gap separation 0.25 mm is connected to a 30 V battery, and fully charged. The battery is then disconnected. I Solved most of the parts of this q's but not this one:

The plates are now pulled to a separation of 0.55 mm. What is the charge on the capacitor now?

note:

I found 125.5pC and the answer unit is pC

If the area of a square has increased by a factor of 16, by how much has each side increased?

It may seem strange that the selected velocity does not depend on either the mass or the charge of the particle. (for example, would the velocity of a neutral particle be selected by passage through this device? ) the explanation of this is that the mass and the charge control the resolution of the device--particles with the wrong velocity will be accelerated away from the straight line and will not pass through the exit slit. if the acceleration depends strongly on the velocity, then particles with just slightly wrong velocities will feel a substantial transverse acceleration and will not exit the selector. because the acc

In addition to gravity, what is the other predominant force that affects the motion of a pendulum?