Free Fall Time Calculator

Calculate the time required for objects to fall specific distances or reach certain velocities during free fall

Calculate Free Fall Time

Distance the object will fall

m/s

Starting velocity (0 for objects dropped from rest)

m/s²

Gravitational acceleration (9.80665 m/s² for Earth)

Unit for displaying the calculated time

Free Fall Time Results

0.000
Fall Time (seconds)
0.00
Height (m)
0.00
Final Velocity (m/s)

Formula used:t = √(2h/g)

Input values: Height: 0.00m, Initial velocity: 0m/s, Gravity: 9.80665m/s²

Time in seconds: 0.0000 s

Physics Analysis

Example Calculations

100 ft Drop (No Initial Velocity)

Given: h = 100 ft = 30.48 m, v₀ = 0 m/s, g = 9.80665 m/s²

Formula: t = √(2h/g)

Calculation: t = √(2 × 30.48 / 9.80665)

Result: t = 2.49 seconds

Reaching 50 m/s from Rest

Given: v = 50 m/s, v₀ = 0 m/s, g = 9.80665 m/s²

Formula: t = (v - v₀) / g

Calculation: t = (50 - 0) / 9.80665

Result: t = 5.10 seconds

Moon Gravity (50m height)

Given: h = 50 m, v₀ = 0 m/s, g = 1.625 m/s²

Formula: t = √(2h/g)

Calculation: t = √(2 × 50 / 1.625)

Result: t = 7.85 seconds

Free Fall Time Equations

Time from Height (v₀ = 0)

t = √(2h/g)

For objects dropped from rest

Time from Height (v₀ ≠ 0)

t = (-v₀ + √(v₀² + 2gh)) / g

For objects with initial velocity

Time from Velocity

t = (v - v₀) / g

Time to reach target velocity

Quadratic Form

h = v₀t + ½gt²

General height equation

Fall Time Examples

Common objects and their fall times:

1 meter drop:0.45 s
10 meter drop:1.43 s
100 meter drop:4.52 s
500 meter drop:10.10 s
1000 meter drop:14.28 s

Note: These times assume no air resistance and Earth gravity

Real-World Considerations

⚠️

Objects reach terminal velocity due to air resistance

⚠️

Terminal velocity varies by object shape and mass

ℹ️

Human terminal velocity: ~56 m/s (120 mph)

ℹ️

Raindrop terminal velocity: ~9 m/s

This calculator ignores air resistance for simplified calculations

Understanding Free Fall Time

What is Free Fall Time?

Free fall time is the duration an object takes to fall a specific distance or reach a certain velocity when only gravity acts upon it. It's independent of the object's mass and depends only on the initial conditions and gravitational acceleration.

Key Principles

  • All objects fall at the same rate in vacuum
  • Time depends on height, initial velocity, and gravity
  • Quadratic relationship between time and distance
  • Linear relationship between time and velocity

Formula Derivations

From Basic Kinematics

Position: h = v₀t + ½gt²

Velocity: v = v₀ + gt

Solving for time gives different forms

Quadratic Solution

For height: ½gt² + v₀t - h = 0

Using quadratic formula:

t = (-v₀ ± √(v₀² + 2gh)) / g

Practical Applications

  • Physics Education: Understanding motion and gravity
  • Engineering: Designing safety systems and timing
  • Aviation: Calculating drop times for equipment
  • Sports: Analyzing jumping and falling motions

Important Limitations

  • ⚠️No Air Resistance: Real objects experience drag
  • ⚠️Terminal Velocity: Maximum speed due to air resistance
  • ⚠️Altitude Effects: Gravity and air density variations
  • ⚠️Object Properties: Shape and mass affect real falls