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What is a good example of instantaneous speed

An open cart is moving along a straight frictionless horizontal track. when rain starts falling vertically into the cart, what happens to the speed of the cart?

A2.0 μf capacitor and a 4.0 μf capacitor are connected in series across a 0.827-kv potential. the charged capacitors are then disconnected from the source and connected to each other with terminals of like sign together. find the voltage across each capacitor.