In this lesson, students will understand how a simple pendulum swings back and forth through oscillatory motion, how time period is defined, and how length affects the time period. They recognize the mean and extreme positions, how oscillations repeat, and why pendulums help measure time.
Students will be able to:
Reference: NCERT Book Alignment
The lesson is aligned with the NCERT Grade 7 Science Textbook, Chapter 8: Measurement of
Time and Motion, Section 8.1 – Measurement of Time.
By the end of the lesson, students will be able to:
In this session, students will explore how a pendulum moves periodically, how to measure its time period using repeated swings, and how the length influences its motion. They will observe why pendulums are used in clocks and how rhythmic motion helps measure consistent intervals of time.
| Title | Approximate Duration | Procedure | Reference Material |
|---|---|---|---|
| Engage | 5 | Show a short clip of a swing or pendulum in motion; ask: “How does it keep moving back and forth without anyone pushing it?” | Slides |
| Explore | 12 | Provide pendulum setup materials. Students identify mean and extreme positions and observe oscillations. | Slides |
| Explain | 10 | Teach the flow: displacement → oscillation → time for 10 oscillations → time period calculation → effect of length vs mass. | Slides + Virtual Lab |
| Evaluate | 10 | Students will attempt the Self Evaluation task on LMS | Virtual Lab |
| Extend | 5 | Think-pair-share: If you double the length of the pendulum, what do you think will happen to the time period? Why? | Slides |
In this session, you will explore how a simple pendulum swings back and forth in a regular pattern, why this motion is called oscillatory, and how the time period helps measure time. You will link these ideas to real-world applications such as clocks and scientific timing experiments.
Why learn this?
Have you seen a swing move steadily even after you stop pushing it?
Clocks use repeating motion—why do they keep ticking regularly?
Real-life link:
A pendulum’s steady, repeating motion makes it useful for measuring equal intervals of time. Understanding this helps you explore how motion, energy, and timing are connected.
This leads to understanding how oscillations occur and why the time period remains nearly constant.
What is a simple pendulum?
A simple pendulum consists of:
When displaced slightly and released, it swings back and forth.
Key components:
Quick example:
A pendulum moving from O → A → O → B → O completes one oscillation.
How does a pendulum move?
Time period measurement
Warm-up example:
If the pendulum takes 22 seconds to complete 10 oscillations:
Time period = 22 ÷ 10 = 2.2 seconds
Simple rules
Solved example
Q: Why does increasing the length increase the time period?
A: A longer pendulum travels a larger arc, so it takes more time to complete one oscillation.
Why is it useful?
Understanding pendulums helps in:
This is the list of vocabulary terms used throughout the lesson.
In this VR lab, you will explore the working of a simple pendulum, an everyday example of periodic motion. You will observe how the pendulum swings, measure the time period for one complete oscillation, and relate it to the angle of displacement.
This lab demonstrates how time, motion, and gravity interact in oscillatory systems.
Open the Virtual Lab and navigate to the Introduction section to learn the concept of a simple pendulum.
Click Start to begin the simulation.
Use the slider at the top-right corner to set the angle of the pendulum.
Once the angle is set, click the Drop button to release the pendulum.
Watch the motion until the pendulum completes one full oscillation (back and forth).
Repeat the process with different angles using the slider to observe how the time period varies with the displacement angle.
Quick Quiz
At the end of the lab, take the quiz to test your understanding of the concepts. Answer the questions and receive immediate feedback on your responses to reinforce learning.