Confused about Circular motion. (1 Viewer)

[sugaryblue]

Oh gosh... I didn't realise how confused I am until today, when i was practising some ciriular motion questions.

Hope it's not too late to ask

I don't get the circular motion question in 1992 paper of any of the d(feifta)/dt and how to express it in terms of radius and velocity.

Can i ask what exactly is (feita)(dot) and (feita)(dot dot)??

Please help me someone, where can I read a detail analysis of this??

 

[Saul]

???

 

[underthesun]

You mean theta. Theta dot is the angular velocity, or rate of change of theta.

Theta dot dot is the angular acceleration.

Velocity = radius times theta (or feita)

well, just a tip, don't exhaust yourself tonight. Most maths problems in the HSC is supposedly able to be done if you've got the basics, because they always have lead-up questions. GL

 

[tonberry_kun]

do past papers only as practice for ur "methods"... maths isnt really a cram subject as opposed to something like physics where u just memorise alotta stuff, maths is more learning the methods, and practising on past papers as they won't ask u the same questions every year as they do in subjects like physics etc.

 

[sugaryblue]

Originally posted by underthesun
You mean theta. Theta dot is the angular velocity, or rate of change of theta.

Theta dot dot is the angular acceleration.

Velocity = radius times theta (or feita)

well, just a tip, don't exhaust yourself tonight. Most maths problems in the HSC is supposedly able to be done if you've got the basics, because they always have lead-up questions. GL

but i don't understand most basics in mechanics. it's my worst topic. no matter how hard I tried to study it.

if theta is angular velocity, what is w? ARGH

 

[ricenoodles]

w = angular velocity

at least i think it is...i dunno my circular motion part of mechanics is shocking...resisted motion is much better

 

[underthesun]

Theta dot = w

Theta dot dot = w dot.

Well, just adding a dot to them. Mechanics is just resolving forces, just look at one or two examples quickly tonight. good luck

 

[tonberry_kun]

w is v/r aint it?

 

[sugaryblue]

Originally posted by underthesun
Theta dot = w

Theta dot dot = w dot.

Well, just adding a dot to them. Mechanics is just resolving forces, just look at one or two examples quickly tonight. good luck

thanks that clarify that part.

if theta dot = w= angular velocity, then I guess x(dot)= -rsin(theta)(theta dot) is just the resolved part of it??

 

[underthesun]

Sorry i gotta say, that on my first post, velocity = radius times (theta dot) = radius times w

for that x(dot), what are you taking as the axis? I haven't got the 1992 paper here with me

 

[sugaryblue]

Originally posted by tonberry_kun
w is v/r aint it?

v = rw
a = rw^2 = v^2 over r

 

[tonberry_kun]

ah goodo
hope they have conical pendulum this time
or banked...
as long as its not that first one... those circle ones argh

 

[freaking_out]

btw, its "theta" not feita.

goodluck everyone!