Q. A balloon rises at at constant velocity of 3m/s. A rock is released over the side. 4.5 seconds later this rock hits the ground. Calculate the height of the rock when it is halfway between the balloon and the ground. Assume Earth gravity (-9.81m/s), neglect air resistance.
Q. The capacitor is now reconnected to the battery, and the plate separation is restored to d. A dielectric plate is slowly moved into the capacitor until the entire space between the plates is filled. Find the energy U2 of the dielectric-filled capacitor. The capacitor remains connected to the battery. The dielectric constant is .
Express your answer in terms of A, d, V, K, and e0.