PhET/C2/Energy-Skate-park/English

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Visual Cue Narration
Slide Number 1

Title slide

Welcome to this tutorial on Energy Skate Park simulation.
Slide Number 2

Learning objectives

In this tutorial We will,

Demonstrate Energy Skate Park, PhET simulation.

Slide Number 3

System Requirements

Here I am using-

Ubuntu Linux OS version 14.04

Java version 1.7.0

Firefox Web Browser version 53.02.2

Slide Number 4

Pre-requisites

To follow this tutorial,

Learner should be familiar with topics in high school Physics.

Slide Number 5 & 6

Learning Goals

Using this simulation we will learn,

About law of conservation of energy.

To show Pie Chart and Bar Graphs for energy changes.

To use Energy vs Position graph to show the energy value at a particular position.

To change Location and observe the energy changes.

About change in energy due to change in Mass and Friction.

Slide Number 7

Law of Conservation of Energy

According to law of conservation of energy,

Energy can neither be created nor destroyed.

It can only be converted from one form to another.

The total energy before and after the transformation is conserved.

Slide Number 8

Potential Energy

PE = mgh

m=mass of object(kg),

g=acceleration due to gravity (m/s2)

h=height (m)

Potential energy is the energy possessed by an object by virtue of its position.

PE = mgh

where,

m is mass of object

g is acceleration due to gravity and

h is height

Slide Number 9

Kinetic Energy

KE =1/2 mv2

m is mass of object (kg)

v is velocity (m/s)

Kinetic energy is the energy possessed by a body due to its motion.

KE =1/2 mv2

where,

m is mass of object and

v is velocity

Let us start the demonstration.
Slide Number 10

Link for PhET simulation

http://phet.colorado.edu

Use the given link to download the simulation.

http://phet.colorado.ed

Point to Energy skate park simulation. I have already downloaded, Energy skate park simulation to my Downloads folder.
To open java file,

Press Ctrl+Alt+T keys.

Type cd Downloads and press Enter.

To run the simulation, open the terminal.

At the prompt type cd Downloads and press Enter.

Type java -jar energy-skate-park _en.jar >> press Enter.

Point to interface.

Then type, java space hyphen jar space energy-skate-park_en.jar and press Enter.

Energy Skate Park simulation opens.

Point to interface. This is the interface of Energy skate Park simulation.
Cursor on the interface. Using this simulation,

let's see how energy transformations happen in real world applications.

Point to menu bar.

Point to File, Tracks and Help.

Screen has a menu bar with menu items-

File

Tracks

Help

Point to skater.

Click on Track menu.

Click on each track.

Screen has a PhET skater oscillating in a default loop.

To change the track of the skater, click on Tracks menu.

Menu shows a list of tracks to choose.

Point to panel on the right side of screen.

Point to each tool.

On the right side, there is a panel with controls.

These controls are used to, change the attributes in the simulation.

Click on Reset button.

Click on Yes.

Click on Reset to reset the simulation.

Click on Yes to confirm the reset.

Click on Choose Skater button.

Point to Choose Skater list.

Click on Choose Skater button on the panel.

Choose Skater panel opens.

Point to each Skater and their mass.

Point to PhET Skater and mass.

Click on Ok button.

This panel shows different skaters along with their mass.

By default PhET Skater with 75 kg mass is selected.

Click on Ok button.

Point to Sim Speed slider.

Point to Play/Pause button, Step button.

Point to Zoom in and zoom out buttons.

At the bottom of the screen we have,

Sim Speed slider to control the speed of the animation.

Play/Pause and Step buttons.

Zoom in and zoom out buttons.

Point to Sim Speed slider.

Drag the sim speed slider in between slow and fast.

By default Sim Speed slider is on fast.

Drag the Sim speed slider between slow and fast.

Click on Show Path button.

Point to purple dots.

Click on Stop button and then Pause button.

To show the path, click on Show Path button in Path section.

Observe the purple dots on the track.

Click on Stop button and then pause the simulation.

Click on Purple dot.

Point to energies, height and speed.

Click on any purple dot on the track.

The following information will be displayed:

Kinetic energy

Potential energy

Total energy

Height

Speed of skater.

Click on Clear button. Click on Clear button to clear the path.
Click on Play button. Now click on Play button to play the simulation.
Click on Show Pie Chart check box. On the right side panel under Energy Graphs section, click Show Pie Chart checkbox.
Point to with Thermal checkbox.

Point to pie chart.

Observe that with Thermal checkbox also gets selected.

Pie chart shows conversion of Kinetic energy to Potential energy and vice-versa.

Point to energy indicator box.

Point to each energy in the panel.

Energy indicator box is shown on the top right corner of the screen.

This box helps to identify the energy changes in the Pie Chart.

Cursor on screen. In this case potential energy is gravitational potential energy.

It is due to change in height of the skater in the gravitational field.

Point to energy changes in the Pie chart when skater moves downwards. As the skater moves downwards, his Potential energy decreases and Kinetic energy increases.
Point to energy changes in the Pie Chart when skater moves upwards. As skater moves upwards his Potential energy increases and Kinetic energy decreases.
Drag the sim speed slider towards Slow. Drag the sim speed slider towards Slow.
Point to Pie Chart.

Point to Pie Chart.

You can still see a small amount of Potential energy at the bottom of the track.

This is because track is at a height above the ground level.

Drag the track to ground.

Point to Pie Chart.

Drag the track to the ground level.

Observe that skater has zero Potential energy at the bottom of track and zero kinetic energy at the top.

Drag the track above the ground level.

Click on Potential Energy Reference checkbox.

Point to P.E=0 at this dotted line.

Now I will drag the track above the ground level.

Click on Potential Energy Reference checkbox.

P.E=0 at this dotted line will display at the bottom of the screen.

Drag Potential Energy Reference line upwards.

Point to Pie Chart.

Drag Potential Energy Reference line upwards to touch the bottom of the track.

Observe that now skater has zero Potential energy at the bottom of the track.

Click on Bar Graph button.

Point to four energies in Bar graph.

Point to Bar Graph.

Next, click on Bar Graph button.

A Bar graph with four energies is shown.

Note the energy changes as the skater moves back and forth on the track.

Point to Total energy in Bar Graph. Here Total energy of the skater remains constant.

Therefore it obeys the law of conservation of energy.

Click on blue point and drag it upwards.

Point to Bar Graph.

Close the Bar Graph.

Let us change the shape and height of the track.

Click on any blue point and drag.

Note the increase in Total energy with an increase in height of the track.

Close the Bar Graph.

Click on Reset button>>In the confirm box click Yes. Click on Reset button to reset the simulation.
Click on Energy vs. Position button.

Point to Energy(joules) vs. Position(meters) graph.

Next click on Energy vs. Position button.

Energy(joules)vs.Position(meters) graph will display.

Drag the track to the left side of screen. Drag the track to the left side to view the graph and skater simultaneously.
Point to Energy vs. Position graph.

Point to moving dotted line.

Point to moving dotted line.

Notice the energy changes with respect to position of skater.

Here you can see a moving dotted line.

It represents, energy of the skater at a particular position on the track.

Point to four energy check boxes.

Click on Thermal energy check box.

Click on Pause button.

Graph has four energy check-boxes at the bottom.

To view the graph of any specific energy, uncheck remaining check boxes.

Click on Pause button to pause the simulation.

Point to Copy button.

Point to graph.

Close the Energy vs. position graph.

Click on Copy button.

Copy button helps to show the energy values at particular position on the graph.

Close the graphs.

Click on Energy vs. Time button.

Point to Energy vs. Time graph.

Now click on Energy vs. Time button.

Energy vs. Time graph opens.

Point to sim speed slider, Stop/Go, Playback, Step, Rewind and Clear buttons. At the bottom of the graph we have-

Sim Speed slider, Stop/Go, Playback, Step, Rewind and Clear buttons.

Click on Play button. Click on Play button to play the simulation.
Click on Stop button. Click on Stop button.
drag the sim speed slider between slow and fast.

Click on Playback button.

Lets drag the sim speed slider between slow and fast.

Then click on Playback button.

Point to violet vertical line.

Point to kinetic, Potential and Total energy values.

Notice a violet vertical line moving across the path.

Note the kinetic, Potential and Total energy values at a given time.

Point to Total energy.

Point to Kinetic energy and Potential energy values.

Point to Thermal energy value.

Close the Energy vs. Time graph.

Note that Total energy remains constant.

But, Kinetic energy changes to Potential energy and vice-versa.

Here Thermal energy is zero as there is no friction.

Close the Energy vs. Time graph.

Click on Reset button>>In the confirm box click Yes. Click on Reset button to reset the simulation.
Cursor on interface.

Scroll to the bottom of the panel.

Let us see how mass of the skater will affect the total energy.

Scroll to the bottom of the panel.

Click on Edit skater button.

Scroll down>>>Point to Mass text-box and slider.

Point to 75 kg mass.

Click on Edit skater button.

Scroll down to see Mass text-box and Mass Slider.

By default Mass is 75 kg.

Click on Energy Vs. Time button. Click on Energy Vs. Time button to open the graph.
Drag the Mass slider gradually towards 200.

Point to kinetic, potential and Total energy values.

Drag the Mass slider gradually towards 200.

Observe the change in energy as we change the skater's mass in the graph.

Close the Energy Vs. Time graph. Close the Energy Vs. Time graph.
Now we will take the skater to different planets.
Scroll up the panel.

Click on Reset button>>In the confirm box click Yes.

Point to Earth In the Location section.

Click on Energy vs. Time button.

Scroll up the panel.

Click on Reset button to reset the simulation.

In the Location section, by default Earth is selected.

Click on Energy vs. Time button.

Click on Moon radio-button.


Point to skater and Gravity value.

Under Location section, click on Moon radio-button.

Observe that Skater flies off beacause moon has low Gravity value.

Click on Return Skater button. Click on Return Skater button.
Point to Gravity text-box.

Point to skater.

Point to Total energy value.

Here Gravity value is 1.62 N/kg which is less than that of Earth.

This results in decrease in the speed of skater.

Here Total energy decreases as gravity on Moon is less than that of Earth.

Cursor on interface.

Close the Energy vs. Time graph.

Similarly explore Jupiter and Space locations and compare the energy changes.

Close the Energy vs. Time graph.

Cursor on the interface. Let us study the energy distribution for tracks with and without Friction.
Click on Reset button>>In the confirm box click Yes. Click on Reset button to reset the simulation.
Scroll down>>Click on Track Friction button.

Point to Coefficient of Friction slider.

Click on Energy vs. Time button.

Scroll down to panel and click on Track Friction button.

Scroll down to see Coefficient of Friction slider.

Click on Energy vs.Time button.

Drag the Coefficient of Friction slider slowly.

Point to Total energy.

Point to Thermal energy.

Drag the Coefficient of Friction slider gradually from None to Lots.

Observe the energy changes.

Here part of energy is converted to Thermal energy due to Friction.

Cursor on interface.

Point to skater.

This is due to the resistance in motion caused by Friction.

Friction opposes the motion of the skater.

It causes him to lose energy and slow down.

Close the Energy vs. Time graph.

Slide Number 11 & 12

Assignment 1

As an assignment,

Select Double Well track from Tracks menu and observe the energy changes.

Compare the energy changes in Double well track with Double Well Roller Coaster Mode.

Find the changes in the thermal energy .

And give an explanation.

(Hint-Right click on the Track and select Roller Coaster Mode)

Slide Number 13

Assignment 2

Using Tracks box,

Create tracks and observe the change in energies.

Let us summarise.
Slide Number 14

Summary

In this tutorial we have demonstrated,

How to use Energy Skate Park, PhET simulation.

Slide Number 15 & 16

Summary

Using this simulation we have learnt,

About law of conservation of energy.

To show Pie chart and Bar Graphs for energy changes.

To use Energy vs Position graph to show the energy value at a particular position.

To change Location and observe the energy changes.

About change in energy due to change in Mass and Friction.

Slide Number 17

About Spoken Tutorial project

The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

Slide Number 18

Spoken Tutorial workshops

The Spoken Tutorial Project team:

conducts workshops using spoken tutorials and

gives certificates on passing online tests.

For more details, please write to us.

Slide Number 19

Forum for specific questions:

Do you have questions in THIS Spoken Tutorial?

Please visit this site Choose the minute and second where you have the question. Explain your question briefly Someone from our team will answer them.

Please post your timed queries on this forum.
Slide Number 20

Acknowledgements

This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
Slide Number 21

Acknowledgement

Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

This is Meenal Ghoderao from IIT-Bombay.

Thank you for joining

Contributors and Content Editors

Meenalghoderao, Snehalathak