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Basic Theory Behind the Experiment
The experiment “Effect of Mass on Period of a Simple Pendulum” aims to investigate how the mass of an object hanging from a string affects the time it takes for the pendulum to swing back and forth, known as its period. This experiment is a fundamental demonstration of a physics concept and can help us understand the relationship between mass and the motion of a pendulum.
In this experiment, we’ll be working with a simple pendulum, which consists of a mass (called the pendulum bob) attached to a string or rod of fixed length. When the pendulum bob is displaced from its equilibrium position (the vertical hanging position), it experiences a restoring force due to gravity. This force causes the pendulum bob to oscillate back and forth.
What You’ll Need
1. Three pendulum bobs of different masses (can be a small weight like a metal ball).
2. A string to hang the pendulum bob from.
3. A ruler to measure the length of the pendulum.
4. A timer or stopwatch to measure the period of the pendulum swings.
5. A clamp or support stand to hang the pendulum.
6. A protractor or angle measuring tool.
Procedure
1. Set up the Pendulum: Attach the pendulum bob to the string. Ensure that the pendulum is free to swing without any obstructions.
2. Measure Length: Use the ruler to measure the length (L) of the pendulum from the pivot point to the centre of mass of the pendulum bob. Record this length in meters (m).
3. Initial Swing: Pull the pendulum bob to one side, and then release it from a small angle (not exceeding 10 degrees) from the vertical hanging position. Ensure that the pendulum swings in a straight line without any lateral motion.
4. Time the Period: Gently pull the pendulum to one side and release it. As it swings back and forth, start your timer. Measure how long it takes for the pendulum to complete ten full swings (ten oscillations) and divide it by 10. This is your “period” for that trial.
5. Repeat: Repeat the above steps for different masses of the pendulum bob while keeping the length of the pendulum constant.
6. Record Data: Record the period (T) for each mass of the pendulum bob.
Observations:
The period (T) of the pendulum does not change with different masses.
FAQs on Effect of Mass on Period of a Simple Pendulum
What is a simple pendulum?
Ans: A simple pendulum is a mass (known as the pendulum bob) attached to a string or rod of fixed length that can swing freely in a gravitational field.
How does the mass of a pendulum bob affect its period?
Ans: The mass of the pendulum bob does not affect its period; the period depends solely on the length of the pendulum and acceleration due to gravity.
Can the mass of the string or rod affect the period of a pendulum?
Ans: In most cases, the mass of the string or rod is negligible and doesn’t significantly affect the period.
What happens to the period of a pendulum if you conduct the experiment on the Moon’s surface (where gravity is weaker)?
Ans: The period would increase because the acceleration due to gravity on the Moon is weaker than on Earth.
What is the formula for calculating the period of a simple pendulum?
Ans: The formula is T = 2π√(L/g), where T is the period, L is the length of the pendulum, and g is the acceleration due to gravity.
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