unity 2D physics on android devices

i wanna run my game on an android device i already try it on andy emulator on my macbook and it performed great just how i wanted but wen i try it on an android device the physics go crazy.... the game is about a gameObject (a ball) that u have to make it jump over some obstacles by touching the screen on one side and while it is in the air make it go down faster by touching the other side of the screen but the problem is when i try it on an android phone (in a godmode type so i can test it's collisions) when the ball collide with an obstacle after making it go down faster the ball bounces off like crazy and make it very hard to control it so should i make changes to the weight of the gameObject and the gravity scale and try it every single time on an android or is there any other way ????