Edexcel A2 Physics Unit 5 'Physics from Creation to Collapse'

now its perfect .. another question how do i know when to use cos or sin for getting displacement?

now its perfect .. another question how do i know when to use cos or sin for getting displacement?

always use cos 4 displacement..sin for velocity ,cos for acceleration.

could someone explain the displacement-time graph for an overdamped object? I dont get why the displacement does not go all the way to zero

edexcel blue book. page 188 . about astronomical distances

in thw worked example, we have been asked to find distance of the star from the earth. so why have they given distance between sun and the star??? surely its NOT the same thing!!

the oscillation stops before going through its equilibrium position, that's why its graph looks like that!
and btw after a very long period of time, it might reach a displacement of zero!

I just wish if they don't get us anything related to the AS

sorry i dont get it! when you say it stops before going through its equilibrium position, what exactly do we take to be the equilibrium position?
this second question will probably explain itself if i get the first one but what do you mean it might reach a displacement of zero? (an example would probably help)

okay guys. i have this question can someone tell me how to use distances like the relations... for example i know 1 parsec equals to 3.26 light years what about other relations?

no, that's wrong, we use sin and cos depending on the starting position of the oscillating object.
For instance, if it starts at its max displacement ( amplitude ), we use cos for x, however if it starts at its min displacement, we use sin for x.
then we can find the velocity by differentiating the equation of x, and acceleration by differentiating the equation of v..

Good luck everyone
5 and a half hours left!

WHAT????????????
cud u plz do with a little bit of more explanation cuz all this time i have been using cos for displacement and acceleration and sine for velocity!!!!
Thnx

WHAT????????????
cud u plz do with a little bit of more explanation cuz all this time i have been using cos for displacement and acceleration and sine for velocity!!!!
Thnx

it all depends on the starting position!!!
just draw a graph of displacement time graph, for instance if it starts its motion at the amplitude, it would be a cosine graph, so x = A cos (wt)
and v is x's derivative.

Good luck

okay so if the oscillation is starting at maximum which is the extreme point then for calculating displacement you should use cos and then differeniate to get the velocity and acceleration
if in the question its mentioned that it starts from mean position which is the equilibrium position you have to use sin for the displacement and depending on that differentiate for velocity and aceleration

WHAT????????????
cud u plz do with a little bit of more explanation cuz all this time i have been using cos for displacement and acceleration and sine for velocity!!!!
Thnx