šŸŽÆ Free Fall Experiment

Determine Acceleration Due to Gravity (g) using Freely Falling Objects

āœ… FREE Experiment ā€¢ ā±ļø Precision Timing ā€¢ šŸŽ“ NEB Class 11 Practical

Interactive Simulation

Watch the ball fall and measure time to calculate gravity

Experiment Controls

Range: 1 - 10 meters

Recommended: 5 trials for accuracy

Time of Fall
0.000
seconds

Real-Time Results

Drop Height (h)
5.0
m
Time Taken (t)
0.000
seconds
Calculated g
0.00
m/sĀ²
% Error
0.0
%

Observation Table

Trial No. Height (h)
meters		 Time (t)
seconds		 tĀ²
secĀ²		 g = 2h/tĀ²
m/sĀ²
No observations yet. Drop the ball and click "Add to Table"

šŸ“Š Mean Calculation

Mean value of g = 0.00 m/sĀ²

Standard value = 9.81 m/sĀ²

Percentage error = 0.0%

šŸ“š Theory & Concepts

What is Free Fall?

Free fall is the motion of an object under the influence of gravity alone, without any air resistance or other forces. When an object is dropped from rest, it accelerates downward due to Earth's gravitational pull.

Equations of Motion

For an object dropped from rest (initial velocity u = 0), the equations of motion are:

s = ut + Ā½gtĀ²

Since u = 0 (dropped from rest):
h = Ā½gtĀ²

Calculating Gravity (g)

g = 2h / tĀ²

Where:
ā€¢ g = Acceleration due to gravity (m/sĀ²)
ā€¢ h = Height from which object is dropped (meters)
ā€¢ t = Time taken to fall (seconds)

Key Points

Why All Objects Fall Equally?

According to Newton's second law: F = ma
Gravitational force: F = mg
Therefore: mg = ma
This gives: a = g (independent of mass)

This means a feather and a hammer would fall at the same rate in vacuum (no air resistance), as famously demonstrated by astronauts on the Moon!

šŸ”¬ Procedure

  1. Set up a vertical drop tower or use a tall building/structure
  2. Measure the exact height (h) from release point to ground
  3. Hold the ball/object at the measured height
  4. Ensure the object starts from rest (no initial velocity)
  5. Release the object and simultaneously start the timer
  6. Stop the timer when object hits the ground
  7. Record the time (t) accurately in seconds
  8. Calculate tĀ² (square of time)
  9. Use formula g = 2h/tĀ² to calculate gravity
  10. Repeat the experiment 5 times for accuracy
  11. Calculate mean value of g from all trials
  12. Compare with standard value (9.81 m/sĀ²)

šŸ’¬ Viva Questions & Answers

Q1: What is free fall?
Free fall is the motion of an object under the sole influence of gravity, without any air resistance or external forces. The object accelerates downward at g = 9.81 m/sĀ².
Q2: What is the formula to calculate g?
For an object dropped from height h taking time t to fall: g = 2h/tĀ² This comes from the equation h = Ā½gtĀ² (when initial velocity u = 0).
Q3: Does mass affect the time of fall?
No, in the absence of air resistance, all objects fall with the same acceleration g, regardless of their mass. A heavy and light object dropped from the same height will hit the ground simultaneously.
Q4: What is the value of g on Earth?
The standard value of acceleration due to gravity on Earth's surface is 9.81 m/sĀ² or approximately 9.8 m/sĀ². It varies slightly with location (altitude and latitude).
Q5: Why do we neglect air resistance?
For dense, compact objects falling through short distances, air resistance is negligible compared to gravitational force. This allows us to use simple equations and get accurate results for g.
Q6: What are the equations of motion used?
The main equation is s = ut + Ā½atĀ². For free fall: h = ut + Ā½gtĀ². When dropped from rest (u = 0), it becomes h = Ā½gtĀ², which gives g = 2h/tĀ².
Q7: What is the final velocity formula?
Using v = u + at, and for free fall (u = 0, a = g): v = gt. Also, using vĀ² = uĀ² + 2as: vĀ² = 2gh, so v = āˆš(2gh).
Q8: Why do we take multiple readings?
Multiple readings reduce random errors and increase accuracy. Human reaction time errors and measurement uncertainties are minimized when we calculate the mean of several trials.
Q9: What are sources of error?
Main errors include: (1) Human reaction time in starting/stopping timer, (2) Air resistance for light objects, (3) Inaccurate height measurement, (4) Not dropping from complete rest, (5) Timer precision limitations.
Q10: How does g vary with location?
g decreases with altitude (farther from Earth's center) and varies with latitude (maximum at poles, minimum at equator due to Earth's rotation). At sea level, g ranges from about 9.78 m/sĀ² at equator to 9.83 m/sĀ² at poles.