I am having trouble with two concept questions. We did a lab measuring static and dynamic friction for cardboard, rubber, sandpaper, and cork with a wood block. Calculations show that the coefficient of static friction is always greater that that of kinetic friction. The questions are: a) How do the coeffients of static and kinetic frictions compare? Explain. My answer was that the coeff. of static friction is always greater, reason being that it takes a greater force to get an object to start moving from rest (acceleration), which is when static f. was measured, versus just keeping an object moving (a = 0). b) Do "smoother" surfaces always have less friction than "rougher" ones? Ans: No, because it depends on the other surface they are interacting with?? I have tried to answer them, but if someone could just check and point out what is wrong I would appreciate it. I think i got the first question right but i'm pretty sure the second one is wrong.I really don't know how to answer b. What are the concepts behind the second one? Because i truly don't even know where to start with that.