Q. An electric field of 610 V/m is desired between two parallel plates 14.0 mm apart. How large a voltage should be applied?

Q. A 200 g ball on a 60-{cm}-long string is swung in a vertical circle about a point 200 {cm} above the floor. The tension in the string when the ball is at the very bottom of the circle is 5.6 N. At the very bottom of the circle, a very sharp knife is suddenly inserted, to cut the string directly below the point of support. How far to the right of where the string was cut does the ball hit the floor?