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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: #1procrastinator on December 25, 2012, 03:11:54 pm

Title: Centrifugal force question
Post by: #1procrastinator on December 25, 2012, 03:11:54 pm
Say you're holding onto a rope and be whirled around horizontally, the rope pulls on you and provides the centripetal acceleration. In your frame of reference, is it by Newton's third law that you feel a pull outwards (the centrifugal force?). So the action is the rope pulling on you, the reaction is you pulling on the rope and it's this pulling on the rope that makes you feel an outward force?

A similar case is if you're sitting in a chair with a back facing inwards on a rotating turntable, the back of the chair pushes on you cause you're pushing on the chair as your body wants to continue in a straight line.

Is it correct to say these two cases are examples of where Newton's laws are NOT violated in a non-inertial frame? If not, please point out my where I went wrong!

Thanks

Title: Re: Centrifugal force question
Post by: Quantum.Mechanic on December 25, 2012, 03:52:22 pm
Just gonna say its Christmas Day, just relax and have fun today?

They both satisfy Newtons Third Law about Every action having an equal and opposite reaction. It must be the reaction force that provides the outward force as the net force must be equivalent to zero, otherwise you would be moving outwards which does not occur.

I don't understand the reference to non-inertial frame? I don't think that comes up in VCE Physics, at least I haven't come across it whilst reading the textbooks last year, nor on any of the practise exams I have completed.

Title: Re: Centrifugal force question
Post by: #1procrastinator on December 25, 2012, 04:22:16 pm
Haha, I don't care for Christmas, same as other day as far as I'm concerned :p
I'm learning from a college textbook (I'm done with VCE physics). I didn't remember if this was covered in VCE physics or not so I just posted here, plus the general science forum looks dead.

A non-inertial frame is a reference frame that's accelerating with respect to an inertial reference frame and Newton's laws don't hold in these frames but I'd like to know if this is always true.