Resources for "Forces and Interactions in STEP"
| Visual Cue
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Narration
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| Slide 1
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Welcome to this tutorial on how to add forces
and interactions in STEP.
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| Slide 2
Slide 3
Slide 4
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In this tutorial we will look at how to add forces.
Click on Applications, Education and scroll down to STEP to open it
This is where we will open STEP
For an introduction to STEP, please see www.spoken-tutorial.org
In this tutorial, I have worked on Ubuntu version 10.04 LTS and STEP version 0.1.0
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| Slide 5
Slide 6
Slide 7
Slide 8
Slide 9
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In this lesson we will do the following:
Add springs
Simulate a linear motor
Simulate a circular motor
Add gravitational foces
Add a tracer
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| STEP Window
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Now we open the STEP window.
In ths window, we will now add a box.
The size of the box can be changed by
clicking on the properties panel and changing its size here
or by clicking on the box and
dragging along the outline
I have now changed the size of the box.
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| Adding a linear motor
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We will add a linear motor.
A linear motor provides a force that acts on the box
I have added a linear motor by clicking on it.
We can define the value of the force in the properties panel here.
Now we click on simulation.
We will see that the box moves with a uniform linear acceleration
given by the second law of motion.
The blue arrow indicates the direction of force and acceleration.
We also see that the box begins to rotate.
Why is this so?
This is so because the linear motor is not at the centre of mass of the box
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| File Save-As dialog box
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Now we will save the simulation as forces and interactions.
I am waiting for the Save-As Dialog box to open.
We will save this as Forces and Interactions.
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| Adding a circular motor
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We will now delete the linear motor.
A component can be deleted by clicking
on the World Scene and deleting it.
We will now add a circular motor.
I will delete this box and add it again So that I can add a circular motor.
Now I am adding a circular motor.
As usual, we can set the properties of the circular motor, the torque value, in
the properties panel.
Now we will click on simulate.
We will see that the box will rotate counter clockwise.
Now we will remove the box and the circular motor.
We can also delete the components by clicking on the world scene itself.
We click here and delete the circular motor.
We click here and delete the box.
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| Adding springs
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Now we will add two disks and connect them with a spring.
We will add Disk 1. We will add Disk 2.
We will redefine the size of the disk.
And connect them with a spring.
We will now move one of these disks and simulate and see what happens.
I will give one of these disks a velocity in the positive x-direction.
When I click on simulate, I see that the spring moves back and forth.
Now we can stop the simlation.
We saw how two particles when connected by a spring behave.
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| Adding gravitational force
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Now we will delete these disks and spring and add particles and a gravitational force.
We will now add two particles to the world scene.
We have added two particles. Now we will add the gravitational force.
The gravitational force has also been added to the world scene.
Now we will redefine the mass of the first particle to be 1010 kg.
You will notice that the red arrow indicates the direction of the gravitational
force experienced by the second particle towards the first particle.
We will also redefine the color of the 1st particle now which can be done in the
properties panel here. We will choose red for this simulation.
We will add a tracer to the second particle.
A tracer is a component you can add to a particle to track its trajectory or to
track its behavior during a simulation.
If you scroll down the palette, you will find the tracer here.
So we will now add a tracer to the second particle.
Now we are ready to run our simulation.
You will notice that the 2nd particle moved towards 1st particle.
The red arrow gives the direction of the gravitational force and the blue arrow
gives the direction of the velocity of the second particle. This blue line is the
tracer that is attached to the second particle.
Now we have seen how gravitational force can be added to a simulation.
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We will now review what we have learnt so far.
We have seen how to add springs, how to add a linear motor, how to add a
circular motor and the gravitational forces and add a tracer.
Now we will look at an assignment to reinforce our understanding.
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| Slide 10
Slide 11
Slide 12
Slide 13
Slide 14
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The assignment is as follows.
Introduce two charged particles
One is positive and the other is negative
Add the electrostatic force
Simulate the interaction when both particles are at rest
Simulate when one of the particles is moving
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| STEP window. Charged particle simulation
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This is how the simulation will look when it is built.
We will click on simulate. This is how the simulation will behave when we
build it.
Please build this simulation for yourself to see how the coulomb force, the
electrostatic force can be added in STEP.
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| Slide 15
Slide 16
Slide 17
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I would like to acknowledge the Spoken Tutorial Project
which is a part of Talk to a Teacher Project
Supported by the National Mission on Education through ICT, MHRD, Government of India
More information:
http://spoken-tutorial.org/NMEICT-Intro
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| Slide 18
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Thank you for joining me on this tutorial on how to add forces and interactions
in STEP. This is Ranjani Ranganathan signing off. Thank you.
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