Teacher Demonstration
Use the live model as a shared screen demonstration before students try their own predictions and observations.
Physics / Newtonian Mechanics
(Left Anchored, Right Free To Slide) Falling Rods
Explore (Left Anchored, Right Free To Slide) Falling Rods as an interactive EJS simulation for mechanics.
.png)
1. Watch or Launch
Launch the Interactive
Open the simulation, adjust the controls, and compare what changes on screen before answering the concept-check questions.
2. Big Ideas
Key idea Rotational motion depends on torque, moment of inertia, and angular motion. The same applied torque produces different angular accelerations when mass is distributed differently.
What Students Can Learn
- Distinguish linear speed from angular speed.
- Relate torque to angular acceleration.
- Recognise moment of inertia as resistance to change in rotation.
- Use rolling or gyroscope behaviour as evidence of rotational dynamics.
Guiding Question
How does changing mass distribution or applied torque affect the rotation?
3. Try the Investigation
Identify the Rotating Body
Decide which object is rotating and where its axis is.
Change the Distribution
Compare cases with mass near the axis and farther from the axis if available.
Observe Angular Motion
Use angular speed, rotation rate, or visible turning as evidence.
Explain with Inertia
Connect the observed change to torque and moment of inertia.
4. Teacher Notes
Lesson Use
Use these models to make rotational inertia visible. Students often know F = ma but need the analogous idea that torque changes angular motion.
Discussion Prompts
Ask: Where is the axis? Is mass close to or far from the axis? What does the same torque do in each case?
Teaching Moves
Ask for one linear-motion sentence and one rotational-motion sentence so students distinguish speed from angular speed.
5. Concept Check
These questions are generated from the topic and the concept illustrated by the simulation. Use them after students have explored the model.
Concept Score
Correct first attempts build a streak and unlock higher point multipliers on this device.
0page points
0current streak
x1multiplier
0best streak
Answer each question once to build your streak.
1. What is moment of inertia?
2. What does a net torque cause?
3. Why does mass distribution matter?
4. What is angular speed?
5. What evidence supports a rotational-motion claim?
Expert Challenge
Unlocks after 3 correct concept-check answers on this page.
1. A student says the same force must always produce the same angular acceleration. What is the best feedback?
2. Why can moving mass farther from the axis make rotation harder to change?
3. What is the best critique of using only linear speed to describe a spinning disk?
4. In a gyroscope or rolling model, what evidence makes the explanation stronger?
5. What is the best expert response to 'net torque is zero, so the object cannot be spinning'?
7. Learning Pulse
Anonymous activity shows this resource is being discovered, revisited, and used by learners in different places.
--currently viewing
--total page views
Where Recent Learners Are From
Country or region is inferred anonymously from server location headers when available. No names, accounts, or IP addresses are shown.
Detecting locations...
Updating anonymous page activity...