Cats are known for their ability to always land on their feet, and do so from great heights. Its time that I explain this to you in the fun language of physics.

When an object is falling, the acceleration component is 9.8 (meters/(second)^2). This times the mass of the object gives the overall force downward. So with that being said, all objects weighing 5kg's dropped from the same height should have the same impact when they hit the ground right?.... Wrong. Drag do to surface area needs to be incorporated and also the impulse at the time of impact.

Cats have an uncanny ability to keep calm in the air, and therefore their muscle stay relatively relaxed. because of this the Impact occures over a longer period of time and since the Impact equation is (change in Force)x(Change in time) the longer that the cat takes to bottom out due to the muscles being relaxed and in control the lower the impulse and therefore lower negative consequences on the animal.  The source for the video below is: https://www.youtube.com/watch?v=3oem-M2tQU4