i was assuming a=9.8, but i guess that was bad physics.
i'm tempted to relate this to f=ma, but there's no mass!
man, the last chapter has twice as many equations as the previous chapters combined. :(
if you are given the coefficient of friction, initial velocity, and asked for the distance traveled, how would you do it? my first instinct is to use the vf^2=vi^2+2a(xf-xi), but i don't think that coefficient of friction is hanging out there for no reason?
1) can velocity starts at not zero? but if all objects have to start moving from somewhere, then wouldn't initial velocity always be zero?
2) can velocity starts at negative?
3) can displacement be negative, or we're always heading in the positive direction?
4) if it's up to us to determine...