PhET/C2/Energy-forms-and-changes/English-timed

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Time Narration
00:01 Welcome to this tutorial on Energy Forms and Changes simulation.
00:07 In this tutorial, we will demonstrate Energy Forms and Changes, PhET simulation.
00:15 Here I am using: Ubuntu Linux OS version 14.04,
00:23 Java version 1.7.0,
00:27 Firefox Web Browser version 53.02.2.
00:33 To follow this tutorial, learner should be familiar with topics in high-school physics.
00:41 Using this simulation, we will learn:

1. To conserve energy in real-life systems.

00:50 2. To compare thermal conductivity of different objects.
00:55 3. About different forms of energy.
00:58 Using this simulation, we will:

1. Predict how energy flows when objects are heated or cooled.

01:07 2. Design energy systems.
01:10 3. Study how energy changes from one form to another.
01:15 Energy is the capacity to do work on objects.
01:20 It is a scalar quantity.
01:23 In SI system, it is measured in joules.
01:27 Energy exists in nature in several forms such as-
01:32 mechanical energy,
01:35 electrical energy,
01:38 thermal energy,
01:40 Light energy and
01:42 chemical energy.
01:45 Use the given link to download the simulation.
01:50 I have already downloaded Energy Forms and Changes simulation to my Downloads folder.
01:57 To run the simulation, open the terminal.
02:01 At the prompt, type: cd Downloads and press Enter.
02:08 Then type: java space hyphen jar space energy hyphen forms hyphen and hyphen changes underscore en dot jar and press Enter.
02:24 Energy Forms and Changes simulation opens.
02:28 The simulation screen has 2 tabs at the top- Intro and Energy Systems.
02:35 By default, Intro screen opens.
02:39 Intro screen helps to predict how thermal energy flows when objects are heated or cooled.
02:47 Left side of the screen has a set of three thermometers.
02:52 Right side of the screen has Energy Symbols check-box.
02:57 Click on Energy Symbols check-box.
03:01 Energy chunks will appear in Iron block, Brick block and Water container.
03:08 Number of chunks is proportional to amount of energy in each of the objects.
03:14 In this set up, the energy transfer is in the form of thermal energy.
03:19 There are two heat regulators to heat or cool the system.
03:24 Heat regulators are provided with stands.
03:28 At the bottom of the screen, we have Normal and Fast Forward radio-buttons to control the speed of animation,
03:37 Play / Pause button,

Step button and

Reset All button.

03:42 Drag the Water container onto the stand.
03:46 Drag and attach the thermometer to the container.
03:50 Now drag and hold the slider of the heat regulator upwards to heat the water.
03:57 As the temperature increases, water evaporates and vapors are observed.
04:04 Also, observe that energy chunks escape into the atmosphere.
04:09 Next, drag and hold the slider of the heat regulator downwards to cool the water.
04:16 As the temperature decreases, water freezes and becomes ice.
04:22 Drag and place the container on the workbench.
04:26 Now, drag the Iron block and place it on the first stand.
04:31 Drag and place the thermometer on the Iron block.
04:35 Move the Brick block and Water container to a side.
04:40 Before you start heating, note the number of energy chunks in the Iron block.
04:46 Observe the temperature on the thermometer.
04:50 Drag and hold the slider of the heat regulator upwards to heat the Iron block.
04:56 Observe that energy from heat is transferred to Iron block in the form of chunks.
05:03 Here, internal energy of Iron block increases.
05:08 This is due to the flow of heat from the heat source to Iron block.
05:13 Observe that some chunks from Iron block escape into the atmosphere.
05:19 This results in decrease in the temperature of Iron block.
05:25 Again heat the Iron block to maximum temperature.
05:29 Drag and place the heated Iron block in the Water container.
05:34 Energy chunks travel from hot Iron block into water.
05:39 This results in decrease in the temperature of Iron Block.
05:44 Water becomes hot and its temperature increases.
05:49 This heat transfer process continues till objects reach thermal equilibrium.
05:55 Let us choose Fast Forward option to make the process faster.
06:03 Now, again place the Iron block on the heat regulator.
06:08 Drag and hold the slider down to cool the Iron block.
06:13 Cool the Iron block until thermometer reaches its minimum temperature.
06:19 Again place the cooled Iron block in Water container.
06:23 Note the temperature changes and energy chunks transformation.
06:29 Now place both the blocks on to the stands.
06:33 Drag and place the thermometer on the Brick block.
06:37 Heat the blocks one by one until you will see maximum rise in temperatures.
06:44 Wait till thermal equilibrium is established. Observe the decrease in temperatures.
06:53 Observe that Iron block has more number of energy chunks than Brick block.
06:59 This indicates that Iron has more thermal conductivity than Brick.
07:05 As an assignment:

Heat Iron block and Brick block at the same time.

07:13 Place heated Iron block above the heated Brick block. And explain the observation.
07:20 Now we will move on to Energy Systems screen.
07:24 Click on Energy Systems tab.
07:27 Energy Systems screen opens.
07:31 This screen gives an idea about conservation of energy from everyday life.
07:38 Screen at the bottom has a set of- energy sources,
07:43 electrical energy generation systems and receivers.
07:50 Reset All button is available at the bottom right corner of the screen.
07:56 By default, screen has a set up of- Faucet as energy source,
08:02 turbine as electrical energy generation system and Water container with thermometer as a receiver.
08:10 Click on Energy Symbols check-box.
08:14 Forms of Energy panel will display.
08:18 Forms of Energy panel helps you to identify the various forms of energy.
08:24 Now drag the blue slider to turn on the faucet.
08:28 Notice that water flowing from faucet has mechanical energy.
08:34 This mechanical energy turns the turbine which creates electrical energy.
08:40 This energy causes the temperature of the water to increase.
08:45 As the temperature increases, water evaporates and vapors are observed.
08:51 It gives off more thermal energy into the atmosphere.
08:56 Here, energy is conserved as total energy of the system remains constant.
09:02 Let's set up another energy system.
09:06 Here we will select Sun as a energy source.
09:11 Replace the turbine with solar panel.
09:14 Now, instead of Water container, select incandescent bulb.
09:20 In this system, initially there is no cloud.
09:24 Here, the sun is the source of light energy.
09:28 This light energy is absorbed by the solar panel to create electrical energy.
09:34 This electrical energy causes the bulb to glow.
09:38 The incandescent bulb converts electrical energy into a lot of thermal energy and very little light energy.
09:47 This is because the filament gets heated up.
09:51 Next, replace the incandescent bulb with the fluorescent bulb.
09:56 Observe the energy output of fluorescent bulb.
10:00 Notice that the fluorescent bulb releases more Light energy and less thermal energy.
10:07 Therefore fluorescent bulb is more efficient.
10:11 Now let's see the effect of clouds on solar panel.
10:15 Drag the Clouds slider gradually from None to Lots.
10:20 As you drag the slider, clouds appear.
10:24 Due to the presence of clouds, light energy does not reach the solar panel.
10:30 So, generation of electrical energy stops.
10:34 As an assignment:

Select cycle-generator system.

10:41 Explain why the cyclist must be fed in order to continue to pedal.
10:47 Set up different systems and let it run for a while.
10:52 Observe the energy transformations in each system and tabulate your observations.
10:59 Let us summarize.
11:02 In this tutorial, we have demonstrated how to use Energy Forms and Changes, PhET simulation.
11:11 Using this simulation, we have learnt

1. To conserve energy in real-life systems.

11:19 2. To compare thermal conductivity of different objects.
11:24 3. About different forms of energy.
11:27 Using this simulation we have,

1. Predicted how energy flows when objects are heated or cooled.

11:35 2. Designed energy systems.
11:38 3. Studied how energy changes from one form to another.
11:43 The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

11:52 The Spoken Tutorial project team conducts workshops using spoken tutorials and

gives certificates on passing online tests.

12:01 For more details, please write to us.
12:05 Please post your timed queries on this forum.
12:09 This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
12:17 Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

12:29 This is Meenal Ghoderao from IIT-Bombay. Thank you for joining.

Contributors and Content Editors

Madhurig, PoojaMoolya, Sandhya.np14