How to Calculate the Final Velocity From a Fall

Your velocity when falling is subject to the laws of physics.

The speed you travel when falling is subject to the laws of physics. When falling from rest (i.e., your starting velocity is zero), your final velocity in feet per second equals the square root of the product 2gs, where g is the acceleration of gravity (32.17 feet per second squared) and s is the distance you have fallen, measured in feet. This equation can be simplified to v = 8 times the square root of the distance fallen. Knowing this, you can quickly calculate the final velocity from a fall with a scientific calculator.

Things You'll Need

• Scientific calculator

Instructions

1. Measure the distance you have fallen, in feet. For example, say you have fallen 12 feet.

2. Calculate the square root of the distance fallen, using a scientific calculator. In the example, you determine that the square root of 12 is 3.46.

3. Multiply your answer in Step 2 by eight. In the example, you calculate 8 x 3.46 = 27.68. You have determined that when falling 12 feet from rest, your final velocity is 27.68 feet per second.

Tips & Warnings

• You can compute your final velocity after falling for an amount of time t by multiplying the time by the acceleration of gravity: v = 32.17 x t, where t is the time, measured in seconds, and v is the final velocity, measured in feet per second. For example, if you fall for five seconds, your final velocity is v = 32.17 x 5 = 160.85 feet per second.

References

• The Engineering ToolBox: Acceleration of Gravity and Newton's Second Law

Resources

• Calculator: Scientific Calculator