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# couple of circulation motion questions... Watch

1. My questions may look like an essay but don't worry, simple stuff, I'm just jibbing...

1) Okay I've attached a diagram of a stone ( pretty f**cked up anoo) moving with horizontal circular motion. So the string provides the centripetal force for the motion - horizontal component, and mg is the vertical component, so what is the vector sum of these 2 be?

waitt... i get it :P mg is cancelled by a reaction force right?

2) Okay for :

a) a cyclist moving around a bend, the centripetal force is provided by the friction between the cyclist and the road

b) a car going around a bend on a very slippery banked track, the centripetal force is provided by the horizontal component of the reaction force,

my question is why is a not provided by the same force as b is - horizontal component of reaction...?

Off course b can't be provided by friction between tyres road etc as it says very slippery but why is b not the case for a ?

Thanks alot guys
Attached Images

2. As you noted the road is slippery, so you assume that there is no friction on the car, the fact that the road is banked means that the reaction force will have a component parallel to the horizontal axis, rather than being vertical as in case (a)
3. (Original post by VagnTheBrave)
As you noted the road is slippery, so you assume that there is no friction on the car, the fact that the road is banked means that the reaction force will have a component parallel to the horizontal axis, rather than being vertical as in case (a)

ahh of course, makes sense
Thanks alot =]

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