circular motion... eww. (1 Viewer)

[jkwii]

it sucks. but seriously for a moment now.

got 2 Qs. they both from coroneos supplement.

7. if a particle P moves so that its angular velocity about 2 fixed points R and S is the same, prove that P describes a circle passing thorugh R and S.

9. A point P moves with uniform velocity u along the x-axis. A is a fixed point distant a from the x-axis. show that the angular velocity of P about A is ua/r^2. also prove that no matter where the origin is taken on the x-axis this occurs.

 

[lolokay]

9. x = a tan@
dx/d@ = a sec²@
and sec@ = r/a
so dx/d@ = r[/sup]2[/sup]/a
d@/dx = a/r[/sup]2[/sup]
we have dx/dt = u
d@/dx * dx/dt = ua/r[/sup]2[/sup]
= d@/dt

 

[jkwii]

cheers. maybe i need to some more practice.

 

[kayvon]

hi john wee- frikking circular motion- i am very very lost.
i have been staring blankly at textbooks
nothing works