冠冕：物理学，物体改变其（x，y）

Question

I've added my object ( a ball) and when it collide with an object the ball start changing it x an y position even if I apply force just on it y position (up and down)

local physics = require "physics"
physics.start()
--physics.setContinuous( false ) 

    ball = display.newImage("ball.png") --MAIN OBJECT
    ball.x = 100; ball.y = 100
    physics.addBody(ball, "dynamic", {density=.05, bounce=0.1, friction=.2, radius=12})
    screenGroup:insert(ball)
    ball.myName = "ball"

function activateBall(self, event) --APPLY FORCE FUNCTION
    self:applyForce(0, -1.5, self.x, self.y)

end

function onCollision (event) --BALL COLLIDES WITH JUST THIS OBSTACLES 

    if (event.object1.myName == "obst1") or (event.object1.myName == "obst2") then 
    storyboard.gotoScene("restart", "fade", 400)
    audio.stop()

    end

I want the ball to keep it position without starting to move randomly .

Answer 1

A quick solution would be to simply reset the balls x position in every frame.

local ballListener = function( event )
    ball.x = 100
end
Runtime:addEventListener( "enterFrame", ballListener )

Answer 2

Maybe before applyForce() you can setLinearVelocity() for x value to 0, for y to the value you getLinearVelocity() for y value, and then applyForce() you want to. Probably that resets the x velocity you could have after collision.