physics aqa alevel question

LisaPerera

For physics alevel aqa, is a=w^2/r for angular acceleration and a=v^2/r for linear acceleration?
Thank you

Reply 1

Nitrotoluene

Original post

by LisaPerera

For physics alevel aqa, is a=w^2/r for angular acceleration and a=v^2/r for linear acceleration?
Thank you

The expression a=ω^2/r is incorrect.The correct relationship for centripetal acceleration is:a=ω^2r.
The expression a=v^2/r is correct for centripetal (radial) acceleration.
For tangential acceleration (if the speed changes): atang=αr
Centripetal acceleration depends directly on the square of angular velocity and the radius of the circle, not inversely. The confusion often arises because v=ωr; substituting incorrectly can flip the relationship.

Ciao,
Sandro

Reply 2

LisaPerera

Original post

by Nitrotoluene

Isn't one of these equations for linear acceleration?

Reply 3

Dreamcrab0

Original post

by LisaPerera

Isn't one of these equations for linear acceleration?

The formula for radial acceleration is: a_r=rω²
The formula for tangential acceleration is: a_t=rα
And the linear acceleration is just the both of those vectors added, I think

Reply 4

LisaPerera

Original post

by Dreamcrab0

The formula for radial acceleration is: a_r=rω²
The formula for tangential acceleration is: a_t=rα
And the linear acceleration is just the both of those vectors added, I think

what about the equations I gave, im unfamiliar with a=ra, what bout a=v^2/r is that for linear acceleration then?

Reply 5

Dreamcrab0

Original post

by LisaPerera

what about the equations I gave, im unfamiliar with a=ra, what bout a=v^2/r is that for linear acceleration then?

a=v²/r is just a=rω²are both radial acceleration but just in a different format. The second one, a=rω², is when the formula v=rω is substituted into the first formula.