Physics to drwl please help
posted by John .
A crate of oranges weighing 209 N rests on a flatbed truck 2.0 m from the back of the truck. The coefficients of friction between the crate and the bed are μs = 0.41 and μk = 0.20. The truck drives on a straight, level highway at a constant 7.5 m/s.
(a) What is the force of friction acting on the crate?
(b) If the truck speeds up with an acceleration of 2.1 m/s2, what is the force of the friction on the crate?
(c) What is the maximum acceleration the truck can have without the crate starting to slide?
I posted this earlier i understand A now which is zero but part B and C are still confusing I couldn't get those please help me thnks