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Mechanics Practical

Measurement of g by Free Fall

Leaving Cert Physics Practical Notes

These experiments connect motion on paper with motion in real life. This page is written in simple English so students can understand the experiment, the result, and the reason behind it.

LevelHigher and Ordinary
FocusGravity practical
Exam memory lineUse the measured drop distance and the time of fall to calculate the acceleration due to gravity.
LevelHigher and Ordinary
AreaMechanics
Main ideaMeasurement of g by Free Fall
What to say in classUse the measured drop distance and the time of fall to calculate the acceleration due to gravity.
photogatesUse s = 1/2 g t² when the ball starts from rest.
Premium practical diagram for measurement of g by free fall.

Why this practical matters

These experiments connect motion on paper with motion in real life.

Use the measured drop distance and the time of fall to calculate the acceleration due to gravity.

What You Need

Apparatus

  • trolley or moving object
  • track, runway, or pulley setup
  • stopwatch, light gates, or ticker timer
  • metre rule and masses
  • electromagnet or release clamp

Key Formula

s = 1/2 g t^2 (for a drop from rest)

Say the formula out loud before you start the calculation. It helps students and examiners follow your logic.

How To Do It

  1. Set up the measurement of g by free fall apparatus neatly and make sure the scale or meter reading starts from a known point.
  2. Set up the apparatus neatly, keep the same controlled variables, take measurements carefully, and repeat readings so you can average them.
  3. Use the result to explain the physics idea in simple English. Use the measured drop distance and the time of fall to calculate the acceleration due to gravity.

Simple Explanation

Use the measured drop distance and the time of fall to calculate the acceleration due to gravity.

In the lab, we are not just collecting numbers. We are showing a physics rule in a real and reliable way. That is why careful setup, repeat readings, and clear labelling matter so much.

Common Mistakes

  • Changing too many variables at once.
  • Forgetting units on the final answer.
  • Not stating which quantities were kept constant.

Exam Tips

  • Use clear labels on diagrams.
  • Always mention repetition and averaging.
  • Say what causes the result, not only what the result is.
  • State the observation, the method, and the conclusion in that order.

Simulator / Quick Check

Measurement of g by Free Fall simulator
Enter values and press Run.