Free Fall Velocity
Calculate free fall velocity from height or time with v = √(2gh) and v = gt. Free online physics calculator with velocity vs height charts and formula breakdowns for students.
Enter height or time to calculate. Gravitational acceleration g = 9.80665 m/s². If both are provided, height is used.
About This Calculator
The Free Fall Velocity Calculator determines the final velocity of an object falling under the influence of gravity alone, assuming no air resistance. Enter either the drop height (in meters) or the fall time (in seconds), and the calculator instantly computes the final velocity, the total time of fall, and the distance covered using the standard equations of motion under constant gravitational acceleration.
The calculator uses the fundamental free fall formulas derived from Newton's laws of motion. From a given height h, the final velocity is v = √(2gh) where g = 9.80665 m/s² is the standard gravitational acceleration. From a given time t, the velocity is v = g × t, and the distance fallen is h = ½gt². These equations assume the object starts from rest (initial velocity = 0) and experiences no air drag.
Applications of Free Fall Velocity
Free fall calculations are fundamental in physics education, engineering safety analysis, accident reconstruction, and sports science. Understanding impact velocity helps design parachutes, airbags, safety nets, and protective equipment. The velocity vs height chart shows the characteristic square-root relationship: doubling the height increases velocity by only about 41%, which is why high falls are disproportionately more dangerous.
Note: This calculator assumes ideal conditions without air resistance. In real-world scenarios, air drag reduces the final velocity, and objects eventually reach a terminal velocity when drag equals weight. For example, a skydiver reaches about 53 m/s terminal velocity, while a penny falling from a skyscraper tops out around 11 m/s due to its high surface area relative to weight.
Frequently Asked Questions
How do you calculate free fall velocity from height?
From height h, the free fall velocity is v = √(2gh), where g = 9.80665 m/s² is the gravitational acceleration. For example, dropping from 100 meters gives a final velocity of about 44.29 m/s (159 km/h).
How do you calculate free fall velocity from time?
From time t, the free fall velocity is v = g × t, where g = 9.80665 m/s². After 5 seconds of free fall, the velocity reaches approximately 49.03 m/s (176.5 km/h) assuming no air resistance.
What is the free fall velocity formula?
The free fall velocity formula is v = v₀ + g × t for time-based calculation, and v = √(v₀² + 2gh) for height-based calculation. When starting from rest (v₀ = 0), these simplify to v = g × t and v = √(2gh).
What is the value of gravitational acceleration g?
Standard gravitational acceleration is g = 9.80665 m/s² (32.174 ft/s²). This value varies slightly by location: approximately 9.78 m/s² at the equator and 9.83 m/s² at the poles due to Earth's rotation and shape.
Does air resistance affect free fall velocity?
Yes, this calculator assumes ideal free fall with no air resistance. In reality, air drag opposes motion and objects reach a terminal velocity where drag equals weight. For example, a skydiver in belly-down position reaches terminal velocity around 53 m/s (190 km/h).
How long does it take to fall from 100 meters?
From 100 meters, ignoring air resistance, it takes approximately 4.52 seconds to reach the ground. The impact velocity would be about 44.29 m/s (159 km/h).
What is the difference between free fall and terminal velocity?
Free fall is motion under gravity alone with no other forces. Terminal velocity is the constant speed reached when air resistance equals gravitational force, causing acceleration to stop. Free fall velocity increases linearly with time, while terminal velocity is a fixed maximum.