Sven starts walking due south at 6 feet per second from a point 110 feet north of an intersection. At the same time Rudyard starts walking due east at 5 feet per second from a point 150 feet west of the intersection. (a) Write an expression for the distance d between Sven and Rudyard t seconds after they start walking. d= (b) When are Sven and Rudyard closest? (Round your answer to two decimal places.) What is the minimum distance between them? (Round your answer to two decimal places.) d= ft