Q. A 25 g ball is fired with an initial speed v1 toward a 140 g ball that is hanging motionless from a 1.10 m string. The balls have a perfectly elastic collision. As a result, the 140 g ball swings out until the string makes an angle of 37° with the vertical. What was v1?
Q. A potential difference of 160 V is applied across the two collinear conducting cylinders. The radius of the outer cylinder is 15 cm, the radius of the inner cylinder is 10 cm, and the length of the two cylinders is 40.5 cm. How much charge is applied to each of the cylinders.