Centre of gravity
From Algodoo
Centre of gravity
| Language: | English |
|---|---|
| Description: | The centre of gravity of a body is the point in which the mass of the body can be concentrated. Gravity acts as if all the mass of the body is concentrated in that point. This lesson allows the student to explore the concept of gravity and to find the centre of gravity of an irregular body. |
| Target: | Key Stage 3 |
| Category: | Exercise |
| Discipline: | Static forces, Gravity |
| Learning objectives: |
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| In class: | Discuss the centre of gravity.
What does it mean and what effect does this phenomenon have in real life? How can the centre of gravity of a body be found? Discuss possible ways of doing this with the class and put up suggestions on the board. Discuss how this can be visualized and explored in Algodoo. Let the students create scenes in Algodoo using the suggestions you came up with together or let them use their own ideas. Help the students make decisions and ask guiding questions. Encourage the students to follow the procedure Create – Predict – Interact – Evaluate. Allow the students to follow-up and share their experiences in class after the simulation. |
Steps in Algodoo
Create a scene
Create an irregular body, using for example the brush and the CGS-tool, or use a camera to take a picture of your friend and use her shape. Clean-cut the picture and suspend the body using a hinge.
Make a prediction
Estimate the center of graity.
Run/Interact
Start the simulation. The body will probably start oscillating so it might be necessary to help stopping it using the hand tool. When still, glue a massless, vertical, straight line from the hinge. Choose another spot for the hinge and glue another massless, vertical line. Repeat a couple of times to get 3-4 lines through centre of gravity.
Evaluate
Where do the lines intersect?
Compare with the gravity vector.
