unexpected ApplyImpulseAtLocalPoint behaviour

[emicklei]

Hi, i am having trouble using the applyImpulse function because I observe unexpected behavior.

I have a circle body to which I apply an impulse (local point = zero). Right before and after the apply, I log the velocity of the body. Why is it that a positive X component (here 49) is causing a new velocity in the opposite direction?

7:48AM DBG sprites/moveable_sprite.go:44 pre apply impulse vx=-0.2918252140476518 vy=24.166954594470702 fx=49 fy=-3
7:48AM DBG sprites/moveable_sprite.go:46 post apply impulse vx=-37.113445811790115 vy=-8.301002787475994

When apply an impulse on a zero-velocity situation then the resulting movement is as expected.