need some help on this problem:

An irrigation drip arm is 28 feet long and pivots about a center one revolution each hour. A “drip hole” H is located 28 feet from the pivot point.
(a) What is the linear speed of H in units of feet/hour ,feet/minute ,feet/second , and inches/second .
(b) What is the required drip rate (in drips second ) if we
want at least 4 drips for every 1 inch H travels. (The drip rate must be a counting number; i.e. 1,2,3,4,...)
(c) Suppose 10 drips = 1 cc (cubic centimeter).
How many liters flow from H after 25 minutes, assuming the drip rate computed in b.? (1 liter = 1, 000 cc)
(d) How much water flows from H after the arm has made 3 complete revolutions (assuming the drip rate computed in b.)?

(a) v = rω = 28 * 2π ft/hr

Now just convert that to other units as needed
(b) x >= 4 * 28*2π * 12
(c) x drips/hr * 1cc/10drips * 25/60 hr * 1L/1000cc = ____ L
(d) 180/25 * (c)