Hello there what is the question?
Friction is the force that slows down a ball, if their were no friction, it would not stop.
Answer: friction
Answer: The rate constant for the reaction is 
Explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample = 559 min
a = let initial amount of the reactant = 
a - x = amount left after decay process = 



The rate constant for the reaction is 