Sometimes a cat will fall out of a window or balcony—a byproduct, no doubt, of a cat doing cat things. If you have a house cat, your feline's propensity for aerial shenanigans probably doesn't worry you that much: Cats falling from low windows can use their righting reflex to land on their feet like nothing even happened. Fall from a higher story, though—in what researchers call high-rise syndrome—and they may not be as lucky.

But here's the weird part: Cats falling from super high floors *can* survive. A RadioLab episode on this falling cat issue states that cats falling between five and nine stories are the ones most likely to be injured. Fall from a higher story, though, and your odds of survival are better.

But how? How is it possible for a cat falling from a higher height have a greater chance of survival? The answer depends on two things: air resistance and apparent weight.

When an object falls, there are essentially two forces acting on it. There is the downward force of gravity that depends on both the gravitational field (9.8 N/kg on Earth) and the mass of the object. The other force is the air resistance force. The air resistance is a force that increases with the speed of the object and always pushes in the opposite direction as the motion of the object. If I assume the object is only moving in the downward direction, I can write the sum of the forces in the y-direction (vertical direction) as:

For the air resistance force, ρ is the density of air, A is the area of the object, and C is a coefficient that depends on shape. You can see that when the object first starts falling, the velocity would be zero such that the total force would just be -m*g (like a free falling object). One more note: I can estimate the cross sectional area of a cat, but the drag coefficient will be a bit more difficult. When the speed increases to the point where the net force is zero (the gravitational force and the air resistance force balance), then the object will move at a constant speed—we call this the terminal velocity.