Enter the force of air resistance and the object’s mass into the calculator to determine the Free Fall Acceleration. 

Free Fall Acceleration Formula

The following equation is used to calculate the Free Fall Acceleration.

Aff = g - (Fa/m)
  • Where Aff is the Free Fall Acceleration (m/s^2)
  • Fa is the force of air resistance (N)
  • m is the mass of the object (kg)
  • g is the acceleration due to gravity = 9.81 (m/s^2)

To calculate the free-fall acceleration, subtract the division of the air resistance force and mass of the object from the acceleration due to gravity.

What are the units for Free Fall Acceleration?

In the International System of Units, also known as SI units, the units for Free Fall Acceleration are m/s^2.

How to Calculate Free Fall Acceleration?

Example Problem:

The following example problem outlines the steps and information needed to calculate the Free Fall Acceleration.

First, determine the force of air resistance. In this example, the force of air resistance is calculated or measured to be 500 (N).

Next, determine the mass of the object. For this problem, the mass of the object is determined to be 100 (kg).

Finally, calculate the Free Fall Acceleration using the formula above: 

Aff = g – (Fa/m)

Inserting the values from above and solving the equation with the imputed values gives: 

Aff = 9.81 – (500/100) = 4.81 (m/s^2)

FAQ

What factors can affect the calculation of Free Fall Acceleration?

The calculation of Free Fall Acceleration can be affected by several factors including the air density (which influences the force of air resistance), the shape and surface area of the falling object (which also affects air resistance), and variations in the acceleration due to gravity depending on geographical location and altitude.

How does air resistance influence the speed of a falling object?

Air resistance, also known as drag, opposes the motion of an object through the air and thus reduces its acceleration. The greater the air resistance, the slower an object will fall. This is because air resistance works against the force of gravity, reducing the net force and consequently the acceleration of the object.

Can Free Fall Acceleration be negative?

In the context of the given formula, Free Fall Acceleration cannot be negative because it is calculated by subtracting the force of air resistance (divided by mass) from the acceleration due to gravity. Since gravity is a constant positive value (9.81 m/s^2) and the force of air resistance divided by mass would result in a value that is subtracted from gravity, the result is a reduction in the positive value of acceleration, not a negative acceleration. However, if the force of air resistance is greater than the force of gravity (which is unlikely in free fall), the formula might suggest a negative value, but this would be an incorrect application of the concept as it defies the basic principles of free fall.