A 75kg firefighter slides down a pole with a constant friction force of 30N retarding her motion. A horizontal 20kg platform is supported by a spring at the bottom of the pole to cushion the fall. The firefighter starts from rest 4m above the platform, and the spring constant is 4000N/m. Assuming that the friction force acts during the entire motion, find:
(a) the firefighter's speed just before she collides with the platform; and
(b) the maximum distance the spring is compressed.