Duration of Free Fall

The Duration of Free Fall calculator computes time required to fall a distance (h) based on a constant gravitational acceleration (g).  This assumes no initial upward or downward velocity, and no wind resistance.

INSTRUCTIONS: Choose units and enter the following:

• (h) Height or distance of the fall.
• (g) Acceleration due to gravity.

Duration of Free Fall (Δt): The duration is returned in seconds.  However, this can be automatically converted to other time units via the pull-down menu.

The Math / Science

The formula for the duration of free fall is:

         `Deltat = sqrt((2h)/g)`

where:

• Δt = duration of free fall
• h = vertical displacement
• g = acceleration due to gravity

This answers the question, "How long will it take me to free fall a certain distance." 

Free fall is when an object accelerates downwards from rest due to gravity and gravity alone.  For this idealized case of free fall, we shall ignore air resistance and assume that the acceleration due to Earth's gravity is constant.  This allows us to describe free fall as an application of kinematics, where the initial velocity is 0 and the acceleration is g (roughly 9.8 m/s²).  "g" may be taken to be positive or negative depending on exactly how you've defined your directions.

Free Fall Calculators

• Duration (Time) of Free Fall
• Distance (Height) of Free Fall
• Final Velocity of a Free Fall

References

• Light and Matter(Dr. Benjamin Crowell) Chapter 6.2 Coordinates and components