Simple Harmonic Motion (1 Viewer)

[wrxsti]

My textbook has the equation for displacement as x=acos(nt+alpha)
i did all the questions and got em rite...... i went to fitzpatrick book and worked through dose questions about SMH and got em all rong :S ....... they use x=asin(nt+alpha) ummmm which one are you supposed to use? :S

 

[ssglain]

Both should get you the correct answer, but the different forms vary in convenience depending on the initial position of the particle. If this is at an extremum of the motion use x=a*cos(nt+@); at the centre of motion use x=a*sin(nt+@); at anywhere else use x=a*sin(nt) + b*cos(nt).

Why are you asking if you were class of '06?

 

[wrxsti]

this is my bros name... i cant be bothered making a new one

 

[senida]

hey, how is everyone first of all. hope your all studying hard these holidays!!!
TRIALS comin up. lol
well i need a hand with projectile motion. i'm having a lot of trouble with it, i don't know maybe i don't get somethng. i know how to derive the equations and i can do simple questions but some of the questions get really complex. is there a set way of doing them where you can apply one method to every question. i've tried doing past HSC questions and some of them i have no idea!!!

for e.g. have a look at the 2001 HSC question 4 part b, (an aircraft flying horizontally...)
sorry i don't know how to write the question up so you understand. i've looked at the solution and its just too complicated (to me at least).

if you can pleasseeee help me, i'll really appreciate it. thank you.
hope to hear from some one soon!!!