You have two wires made of two different metals(metal A and metal B). Both wires are the same thickness and length. You use both wires in two identical but seperate circuits. Metal A wire gets hot, while metal b dosnt. Why?

Cathy is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling. cathy and her bicycle have a mass of 75 kg. assuming her bicycle is 100% efficient, what would her speed have to be?