Terminal velocity is the speed at which a falling object stops accelerating because the upward force of friction is equal to the downward force of gravity.

Example: a parachutist jumps out of an airplane.

she opens her parachute...

Because cats are have more air friction and less weight, they have a lower terminal velocity that is 50% survivable.

For rats and bugs it is 100% survivable.

Terminal velocity for a human is around 60 m/s or 120 mi/hr, which is almost always fatal.

Since objects traveling at their terminal velocity do not accelerate, we can use the equation

V=d/t to solve for distance or time, even though the motion is vertical.