One question, why does the normal force of a car on a banked road is actually greater than the downwards mg newtons of the car? shouldn't the normal force be simply a reaction force to one of the components of the weight of the car?

 

please help~~~thanks

Ok, what force is needed for circular motion? and where does it come from?

It needs a force pushing the car towards the center... However, that force is a component of the normal force............

yup. so it comes from the normal force. for the normal force to provide this component and for it to not go through the track the normal force has to be <insert word here> than the weight.

 

Its the centrifuge effect.

N = mg implies a static situation, i.e. F = N-mg = 0

 

But a car travelling in a circle is accelerating (centripetal), so F > 0

 

(N_y=mg will still hold true, however)