Determine the value of g by free fall using an electronic timer || Physics Practical || FSC Part 1 |

Episode Overview

• This episode of the Physics Podcast demonstrates a laboratory experiment to determine the value of 'g' (acceleration due to gravity).
• The host explains the necessary equipment, which includes a digital free-fall apparatus, a centisecond timer, an electromagnet, and a metal ball.
• The video walks through the entire experimental procedure, from setting up the apparatus to collecting data at various heights.
• It concludes by detailing the calculations required to find the average value of 'g' from the collected data and how to calculate the percentage error against the accepted value.

Key Concepts

• Free Fall: The experiment is based on the principle of free fall, where a metal ball is dropped and moves solely under the influence of gravity, with air resistance considered negligible.
• Acceleration Due to Gravity (g): The primary goal is to experimentally measure this physical constant, which represents the acceleration of an object in free fall near the Earth's surface.
• Kinematic Formula: The calculation for 'g' is derived from the kinematic equation for motion: h = ½gt². This is rearranged to g = 2h/t², where 'h' is the height of the fall and 't' is the time taken.
• Experimental Error: The concept of comparing the experimentally derived value of 'g' with the known theoretical value (9.8 m/s²) to determine the accuracy of the experiment, expressed as a percentage error.

Quotes

• At 00:07 - "Determination of value of (g) by Digital free fall Apparatus" - The clear statement of the experiment's objective at the beginning of the video.
• At 01:12 - "Find the value of (g) by using the Formula. g = 2h/t²" - Highlighting the core mathematical relationship used to calculate the acceleration due to gravity from the measured height and time.
• At 01:57 - "Time is in centi seconds" - A critical instruction shown during the demonstration, clarifying that the timer's reading must be converted to seconds for the calculation.

Takeaways

• To accurately measure 'g', control variables and minimize human error. Using an electromagnet for release and an electronic trap-door switch for timing automates the process, providing more reliable data than manual methods.
• The accuracy of the final result depends on precise measurements. Repeating the experiment at different heights and then averaging the calculated values of 'g' helps to reduce random errors and provides a more robust final measurement.
• Experimental physics involves acknowledging and quantifying error. Calculating the percentage error (8.5% in this demonstration) is a crucial final step to evaluate the experiment's success and understand the discrepancy between theoretical and measured values.