Ball is rolling down a hill. at one point near the top of the hill, its velocity is 2 m/s. further down the hill, its velocity is 9 m/s. what is δv? 9 m/s 7 m/s -7m/s -7m/s2

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

What will a positive and a negative charge do if they are separated from each other?

Along the line connecting the two charges, at what distance from the charge q1 is the total electric field from the two charges zero? express your answer in terms of some or all of the variables s, q1, q2 and k =14ï€ïµ0. if your answer is difficult to enter, consider simplifying it, as it can be made relatively simple with some work.