Physics question.... car steering related

[halik]

ignoring friction... my and my brother had this argument about car steering. He was trying to tell me that rotational inertia of the wheel causes it to push back at the force applied to make it steer. I thought there was hyroscopic moment involved that redirects the force perpendicular to axis rotation and the direction of the force applied...

Who's right ?

 

[LordMorpheus]

sorta both are . . . the faster the wheel is spinning the more force will be required to rotate it . . . and applying force to rotate a spinning object (around a different object) will cause it to move in a way that seems perpendicular to the applied force (it's bizarre). However, none of this is really related to car steering as the wheel isn't really going fast enough for this to be a meaningful effect . . . unless the car is screaming along, at which point any directional changes to the wheel will be happinig fairly slowly (you don't spin your steering wheel all the way to the right at 120mph . . . you turn it only a fraction, which causes the wheels to just barely change direction relative to the car, and while the car might cause the wheels to turn farther, the wheel will not have nearly enough gyroscopic effect to alter the turn of the car.

 

[mercanucaribe]

I doubt gyroscoping has any effect whatsoever on a car wheel. At highway speed you are moving the wheels at few degrees at the most, probably fractions of a degree. The reason you go straight is that the steering angle is tilted back, so it acts like a caster.