- #1
porquilho
- 2
- 0
Hi. I think this is my 1st post here but I browse a lot on the forum 
I was trying to know the velocity at a point on a rigid Body (in 2D) and i found this equation on a paper:
http://members.fortunecity.de/porquilho/eqVel.jpg
where:
Vap = velocity at point P (body A)
Va1 = Linear Velocity of the Rigid Body CM (m/s)
w1 = Angular Velocity of the Rigid Body (rad/s)
rap with a invers "T" = the perpendicular distance vector from the CM to point p.
Im working on 2 dimension here so angular velocity is just a scalar
The question i have is the unreal result that this equation gives to me, for exemple:
Va1(0, -5)
w1=1.5;
rap(-5,-20) -> now we take the prependicular vector (90º to the left)
rapT(20, -5);
and if I am not mistak making the calculations
Vap = (0,-5) + ( 1.5*20 + 1.5*(-5))
Vap = (0,-5) + ( 30+(-7.5))
Vap = (0,-5) + 22.5 = (22.5, 17.5);
Vap=(22.5, 17.5)
I think this value is too high, are my calculations wrongs ?
HELP ME
I was trying to know the velocity at a point on a rigid Body (in 2D) and i found this equation on a paper:
http://members.fortunecity.de/porquilho/eqVel.jpg
where:
Vap = velocity at point P (body A)
Va1 = Linear Velocity of the Rigid Body CM (m/s)
w1 = Angular Velocity of the Rigid Body (rad/s)
rap with a invers "T" = the perpendicular distance vector from the CM to point p.
Im working on 2 dimension here so angular velocity is just a scalar
The question i have is the unreal result that this equation gives to me, for exemple:
Va1(0, -5)
w1=1.5;
rap(-5,-20) -> now we take the prependicular vector (90º to the left)
rapT(20, -5);
and if I am not mistak making the calculations
Vap = (0,-5) + ( 1.5*20 + 1.5*(-5))
Vap = (0,-5) + ( 30+(-7.5))
Vap = (0,-5) + 22.5 = (22.5, 17.5);
Vap=(22.5, 17.5)
I think this value is too high, are my calculations wrongs ?
HELP ME