The Physics

I don't want to to stand in the slush with a long level checking to see if the road is banked, so I am going to pretend it is level, or that the angle is so slight I can ignore it.
Thompson Drive


Thanks Google maps!
 In the photo, left, I have labeled the radius of the curve, r.free body diagram

Friction pulls the car into the curve
Gravity pulls down
Normal force perpendicular to the road.


y forces: F=ma
    N-mg =ma    a=0
    N=mg
x forces: F=ma          
    f=mac          f=µN ; ac=v2/ r

    µN=mv2/ r
    µmg=mv2/ r ; the m's cancel!
    µg = v2/ r
    v=sqrt (µgr)

speed is related to radius and friction!

Click to the next page for a banked road


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