# Biophysics Problem 15

A cat leaps horizontally from a tree branch $3 \;m$ above the ground. It lands at a point $4 \;m$ horizontal from the point below which it leaped. What is the vertical component of the cat's velocity at the instant it touches the ground?

#### First Step

This is motion in two dimensions, remember that motion in either the horizontal or vertical can be treated independent of the other.

In this problem you can make things easier by letting down be the positive direction.

For the vertical motion, list the three known quantities and the one unknown.

#### Variables

Your list should include:

$u = 0 \\ a = 9.8 \;m/s^2 \\ s = 3 \;m \\ v = ?$

Now with this list, use the proper kinematic equation and solve for $'v'.$

#### Calculations

The calculations are quite simple. After substituting in the values, you should get:

$v^2 = 58.8$

which gives: $v = 7.67 \;m/s$