Now as I understand, a force must be present to cause centripetal acceleration. So as a car goes around a circular arc it is friction between the tires which causes centripetal acceleration. So since the car is turning around the curve the friction will be perpendicular to the instantaneous velocity and therefore towards the center of the arc. So with this I am guessing Ff must be equal to mv2/r or any other form of the centripetal force eqn. But as I see it friction force and centripetal force are the same in this situation and it is directed to the center, now I ask what is holding the car in its path. To me it seems its friction, but isn't friction causing centripetal force. So what is the force in the opposite direction? I know it has to be equal in magnitude. I was thinking centrifugal but not to sure how it works. From what i remember that centrifugal originates from inertia, so if there was no centripetal force able to be exerted the object in uniform circular motion will go off on a tangent. Then I read this: "Caution: In doing problems with uniform circular motion, you may be tempted to include an extra outward force of magnitude mv2/r to keep the body "out there" or to "keep it in equilibrium". This outward force is called the centrifugal force (fleeing from the center). Resist this temptation, because this approach is simply wrong. In an inertial frame of reference there is no such thing as centrifugal force."