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

By what factor does the drag force on a car increase as it goes from 65 to 110 km/h?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?