PhET-Simulations-for-Physics/C2/Energy-Forms-and-Changes/English-timed

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.

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