Hey guys, So we haven't gotten to 3-d objects yet, but i was wondering, since Ff=Fn*mu, what would happen if an object was in a sort of like v, so that it had two normal forces. Lets say it is a box, sliding down a 30degree ramp. The ramp is not just a ramp, but is folded so that it makes a 90 degree angle where the box rests. Because it is 90 degrees, the box is against the surface not only once, but twice, once on the left side of the box, once on the right. So, now that there are two normal forces, which have to be half of the mg i would guess, since the box is not accelerating in the y direction, would the friction also be half? Or is friction eqaul to the sum of Fnormal forces multiplied by Mu. When i think about it just without applying any physics knowledge, it seems like a box being almost encased in a ramp, well at least on two sides, would slide less easily as a box only on one side. Then again, alot of things i have learned in physics are contrary to common knowledge.