- #1
Stephen Bulking
- 54
- 10
A car moving at constant speed is in uniform circular motion, thus having centripetal acceleration of ##a=\frac{v^2}{R}##. The force associated with this acceleration is known to be friction. But friction, in nature, appears as an opposition to the relative motion between two surfaces whether it be static or kinetic friction (Here, the car is neither "sliding" away from the center of the imaginary circle it is rounding nor is it sling towards it, hence the friction of our interest is static friction). Since friction, the centripetal force is directed towards the center of the circle, is there any force acting on the car in the opposite direction? Apparently, no... So is it inertia that friction is fighting against? If so, which is the direction of motion that friction is opposing? Is it the original straight-line motion of the car? Why is it directed to the center of the circle in the first place? Just because it needs to cause radial acceleration?