Develop a Sprite and Platform Game - Unity 4 Game Development - page 42

Tip
Rigidbody - Mass and Drag / Rigidbody2D - Mass and Linear Drag
In Unity Rigidbody or Rigidbody2D , Mass doesn't make the object fall faster or
slower. The speed of the object will depend on gravity and drag. Mass will only
be used when the object is colliding with another, as the higher mass will push the
lower mass more. (Make sure you keep Mass between 0.1 and never more than
10 ). The links to the documentation are as follows: http://docs.unity3d.com/Docu-
mentation/ScriptReference/Rigidbody2D-mass.html and http://docs.unity3d.com/
Documentation/ScriptReference/Rigidbody-mass.html .
Drag or Linear Drag can be used to slow down the object. The higher the drag,
the more the object will slow down. The links to the documentation are as fol-
lows: http://docs.unity3d.com/Documentation/ScriptReference/Rigidbody2D-
drag.html and http://docs.unity3d.com/Documentation/ScriptReference/
Rigidbody-drag.html .