posted by Grant .
A force of 23.0 N is required to start a 3.1 kg box moving across a horizontal concrete floor.
(a) What is the coefficient of static friction between the box and the floor?
(b) If the 23.0 N force continues, the box accelerates at 0.50 m/s2. What is the coefficient of kinetic friction?
How do I find the answer to part b?