zazzy has a math question (1 Viewer)

[zazzy1234]

"the acceleration of an particle is given by a=1/x cm/s2 and the paricle is at rest when it's 3cm to the right of the origin. If the particle is always moving to the right, find the velocity of the particle when its displacement is 10cm (2dp)

answer:1.55

thanx :wave:

 

[Aerath]

I'll help you if you never type in that big purple/pink/red/green/blue/yellow (god forbid) colour again. No guarantees that it's right either.

 

[oly1991]

d/dx(1/2v^2) = (integral of) 1/x
1/2v^2 = lnx + C
when x = 3, v=0.....therefore C = -ln3
when x = 10
1/2v^2 = ln10 - ln3
v^2 = 2ln10 -2ln3
v = (root of) 2ln10 - 2ln3
= 1.55cms^-1

hope that helps

 

[zazzy1234]

THANX 4 DA HELP PEOPLES!!!