Sandhya.np14 at 09:43, 13 August 2018

2018-08-13T09:43:51Z

Madhurig at 12:16, 8 August 2018

2018-08-08T12:16:42Z

PoojaMoolya: Created page with " {|border=1 ||'''Time''' ||'''Narration''' |- || 00:01 || Welcome to this tutorial on '''Gravity and Solar System'''. |- || 00:06 || In this tutorial we will, Demonstrate..."

2018-07-31T09:56:42Z

Created page with " {|border=1 ||'''Time''' ||'''Narration''' |- || 00:01 || Welcome to this tutorial on '''Gravity and Solar System'''. |- || 00:06 || In this tutorial we will, Demonstrate..."

New page

{|border=1
||'''Time'''
||'''Narration'''

|-
|| 00:01
|| Welcome to this tutorial on '''Gravity and Solar System'''.

|-
|| 00:06
|| In this tutorial we will, Demonstrate '''Gravity and Orbits''' and '''My Solar System''', '''PhET simulations'''.

|-
||00:16
|| Here I am using- Ubuntu Linux OS version 14.04

|-
|| 00:23
|| Java version 1.7.0 and

|-
|| 00:27
|| Firefox Web Browser version 53.02.2

|-
|| 00:34
|| To follow this tutorial, Learner should be familiar with topics in high school science.

|-
|| 00:42
|| Using these simulations we will - Describe the relation between Sun, Earth, Moon and satellite.

|-
|| 00:51
|| Study the effect of mass and distance on gravitational force.

|-
|| 00:56
|| Explain how gravity controls the motion of our solar system.

|-
||01:02
|| Identify the variables that affect the strength of gravity.

|-
|| 01:08
|| And determine the gravitational force.

|-
||01:12
|| In our solar system, all the celestial objects revolve around the Sun.

|-
||01:18
|| These objects are planets, moons, comets, asteroids, meteors and meteorites.

|-
|| 01:27
|| There exists a force of attraction between the Sun and the celestial objects.

|-
|| 01:34
|| This force of attraction is '''gravitational force'''.

|-
|| 01:39
|| Let us begin the demonstration.

|-
|| 01:43
|| Use the given link to download the simulation.

|-
|| 01:48
|| I have already downloaded '''Gravity and Orbits simulation''' to my '''Downloads''' folder.

|-
|| 01:55
|| To open the '''simulation''', right click on '''gravity-and-orbits_en.html''' file.

|-
|| 02:01
|| Select '''Open With Firefox Web Browser''' Option.

|-
|| 02:06
|| '''Simulation''' opens in the browser.

|-
|| 02:10
|| This is the interface of '''Gravity and Orbits simulation'''.

|-
|| 02:16
|| The interface has two screens. '''Model'''

'''To Scale'''.

|-
|| 02:22
|| Let us begin our demonstration with '''Model''' screen.

|-
|| 02:26
|| Click on '''Model''' screen to open it.

|-
|| 02:29
|| On the right side of the screen you can see a box.

|-
|| 02:34
|| It has four solar system like models.

|-
|| 02:38
|| Next to models there is a gray coloured, '''Reset''' button.

|-
|| 02:43
|| This button sets the solar system to its default state.

|-
|| 02:48
|| We can select '''Gravity''', using '''on''' and '''off''' radio buttons.

|-
|| 02:54
|| Below '''Gravity''', we have check-boxes for-

'''Gravity Force'''

'''Velocity'''

'''Path''' and

'''Grid''' .

|-
|| 03:03
|| Click on all the check-boxes.

|-
|| 03:06
|| Below this box we have another box.

It consists of sliders to change the mass of '''Star''' and '''Planet'''.

|-
|| 03:15
|| Bottom of the screen we have, '''Fast Forward''', '''Normal''' and '''Slow motion''' radio buttons to change the animation speed.

|-
|| 03:25
|| By default '''Normal''' speed is selected.

|-
|| 03:29
|| Also there are '''Rewind''', '''Play/Pause''' and '''Step buttons'''.

|-
|| 03:35
|| '''Clear''' button to reset the '''Earth Days''' count.

|-
|| 03:39
|| '''Reset''' button to reset the '''simulation'''.

|-
|| 03:43
|| By default '''Sun and Earth''' system is selected.

|-
|| 03:48
|| Now click on '''Play''' button.

|-
|| 03:51
|| Notice that, Earth revolves around the sun along a circular path.

|-
|| 03:57
|| This circular motion is due to '''centripetal force'''.

|-
|| 04:02
|| '''Centripetal force''' causes change in acceleration and keeps the body moving along the circular path.

|-
|| 04:11
|| This force acts towards the center.

|-
|| 04:15
|| This circular path is its orbit.

|-
|| 04:19
|| Earth changes its direction of revolution at every point on the orbit.

|-
|| 04:25
|| Notice that, Direction of Earth's velocity is perpendicular to Sun's Gravitational pull.

|-
|| 04:32
|| Now Let us count '''Earth Days'''.

|-
|| 04:35
|| Click on '''Reset arrow''' to bring the sun and earth to its default position.

|-
|| 04:42
|| Observe the changes in the '''Earth Days''' as earth orbits the sun.

|-
|| 04:48
|| Now we will change the animation to slow to count the days precisely.

|-
|| 05:00
|| Click on '''Pause''' to pause the '''simulation'''.

|-
|| 05:04
|| Earth takes '''365 days''' to complete one revolution.

|-
|| 05:09
|| Next we will see what happens to earth in the absence of gravity.

|-
|| 05:14
|| Click on '''off''' radio button.

|-
|| 05:17
|| Now we will change the animation to normal.

|-
|| 05:21
|| Then click on '''Play''' button.

|-
|| 05:24
|| Observe that, In the absence of '''Gravity''', Earth files off along a straight line.

|-
|| 05:31
|| This motion is tangential to the circular path.

|-
|| 05:35
|| Click on '''Return Objects''' button.

|-
|| 05:38
|| Earth will return to its default position.

|-
|| 05:42
|| Now we will see the effect of change in mass on an orbit.

|-
||05:48
|| By default the '''Star Mass''' slider is at '''Our Sun'''.

|-
|| 05:53
|| Let's drag the '''Star Mass''' slider towards 1.5.

|-
|| 05:58
|| As you drag, observe the increase in size of the star.

|-
|| 06:03
|| Next, click Gravity's '''on''' radio button and then '''Play''' button.

|-
|| 06:10
|| Observe the path of the orbit.

|-
|| 06:13
|| Earth now moves in an elliptical path.

|-
|| 06:17
|| Size of the orbit also becomes small.

|-
|| 06:21
|| Here sun is not at the center of the orbit.

|-
|| 06:26
|| Note that, '''Earth Days''' decrease with the increase in the mass of the sun.

|-
|| 06:32
|| Drag the '''Planet Mass''' slider towards 1.5.

|-
|| 06:37
|| Notice that force of gravity between them increases.

|-
|| 06:42
|| Click on '''Pause''' button to pause the simulation.

|-
|| 06:46
|| Click on the planet and drag it away from the sun.

|-
|| 06:51
|| Click on the '''Play''' button.

|-
|| 06:53
|| Observe that, Gravitational force decreases with increase in the distance between planet and sun.

|-
|| 07:01
|| Click on '''Pause''' button. Click on '''Reset''' button to reset the system.

|-
|| 07:08
|| Now select Sun, Earth and Moon system.

|-
|| 07:12
|| Drag the slider towards '''+''' sign to zoom in the view.

|-
|| 07:17
|| Then click on '''Play''' button.

|-
|| 07:20
|| Notice that, moon is in spiral orbit with earth while earth is in circular orbit with sun.

|-
|| 07:29
|| Here moon is a satellite of the earth.

|-
|| 07:34
|| As an assignment, Using '''Model''' screen, Explore earth, moon and earth, satellite systems.

|-
|| 07:43
|| Now we will move on to '''To Scale''' screen.

|-
|| 07:47
|| Click on '''To Scale''' screen at the bottom of the interface.

|-
|| 07:52
|| '''To Scale''' screen has same tools as that of '''Model''' screen.

|-
|| 07:57
|| This screen has two additional check-boxes-

'''Mass''' and

'''Measuring Tape'''

|-
|| 08:04
|| Click on '''Mass''', '''Path''' and '''Grid''' check-boxes.

|-
||08:09
|| By default sun and earth system is selected.

|-
|| 08:14
|| Here, star's mass is '''333 thousand Earth masses''' and planet's mass is '''1 Earth mass'''.

|-
|| 08:24
|| Click on '''Play''' button to show the path of revolution.

|-
|| 08:28
|| Then click on '''pause''' button.

|-
|| 08:31
|| Lets measure the distance between star and Earth.

|-
|| 08:35
|| Check against '''Measuring Tape''' check-box.

|-
||08:39
|| Uncheck '''Mass''' check-box.

|-
|| 08:42
|| This will enable us to measure the distance precisely.

|-
|| 08:47
|| Drag the zoom in slider towards '''+''' sign to zoom in the view.

|-
|| 08:52
|| Place the '''Measuring Tape''' on star and drag the other end to the planet.

|-
|| 09:00
|| Note the Distance between star and planet.

|-
|| 09:04
|| It is '''91503 thousand miles'''.

|-
|| 09:10
|| This value may vary a little in your case because sun is also in motion.

|-
|| 09:17
|| Let us calculate gravitational force between Earth and sun.

|-
|| 09:22
|| Universal law of gravitation- Force of attraction between any two objects is proportional to the product of their masses.

|-
|| 09:33
|| It is inversely proportional to the square of the distance between them.

|-
|| 09:38
|| This force is along the line joining the centers of two objects.

|-
|| 09:44
|| '''Gravitational force''' is calculated by using following formula

where '''G''' is universal gravitation constant

|-
|| 09:53
|| capital '''M''' is mass of sun

|-
|| 09:58
|| small '''m''' is mass of earth

|-
|| 10:02
|| and '''d''' is distance between earth and planet

|-
|| 10:07
|| We substitute the values of '''G''', capital '''M''', small '''m''' and '''d''' in this formula.

|-
|| 10:15
|| This will give us the value of the Gravitational force between sun and Earth.

|-
|| 10:21
|| The value is '''3.6 x10<sup>22 </sup> N'''(newton).

|-
|| 10:28
|| As an assignment, Using '''To Scale''' screen, Determine the gravitational force between Earth and satellite.

|-
|| 10:37
|| Now we will move on to '''My Solar System PhET simulation'''.

|-
|| 10:43
|| I have already downloaded '''My Solar System simulation''' to my '''Downloads''' folder.

|-
|| 10:50
|| To run the '''simulation''', open the terminal.

At the prompt type '''cd Downloads''' and press Enter.

|-
|| 11:01
|| Then type, '''java space hyphen jar space my-solar-system_en.jar''' and press Enter.

|-
|| 11:17
|| My Solar System '''simulation''' opens.

|-
|| 11:21
|| This is the interface of '''My Solar System simulation'''.

|-
|| 11:26
|| Screen has a system drop-down box on the right side.

|-
|| 11:30
|| Here we can select a pair of solar systems of our choice.

|-
|| 11:36
|| Below the drop-down box there is another box.

|-
|| 11:40
|| It consists of '''Start''', '''Stop''' and '''Reset''' buttons.

|-
|| 11:45
|| We have check-boxes for '''System Centered''', '''Show Traces''', '''Show Grid''' and '''Tape Measure'''.

|-
|| 11:55
|| Use these check-boxes as an when required.

|-
|| 11:59
|| There is a slider to control the speed of animation.

|-
|| 12:03
|| Screen is provided with '''Initial Settings''' at the bottom.

|-
|| 12:08
|| Here we can input the '''mass''', '''position''' and '''velocity''' values in their respective boxes.

|-
|| 12:16
|| We can also use radio-buttons to select a '''number of bodies'''.

|-
|| 12:20
|| Now click on drop down arrow.

|-
|| 12:24
|| Scroll to '''Sun''', '''planet''', '''comet''' and click on it.

|-
|| 12:28
|| We see 3 colored objects planet, sun and comet.

|-
|| 12:37
|| Red coloured arrow indicates the velocity.

|-
|| 12:41
|| It is a vector quantity indicated by '''V''' in circle.

|-
|| 12:46
|| Click on '''Start''' button and observe the orbits. Comet moves around the sun in an elliptical orbit.

|-
|| 12:55
|| Click on '''Stop''' button.

|-
|| 12:57
|| Hover the mouse over '''Sun''', '''Planet''' and '''comet''' to get their '''mass''', '''current position''' and '''velocity'''.
|-
|| 13:09
|| Click on '''start''' button.

|-
|| 13:12
|| After a few revolutions the comet collides with the Sun and disappears.

|-
|| 13:19
|| Select '''Four star ballet''' and click on '''Start''' button.

|-
|| 13:25
|| Observe the orbits. Then click on '''Stop''' button.

|-
|| 13:31
|| Hover the mouse on the bodies to get their '''mass''', '''position''' and '''velocity'''.

|-
|| 13:39
|| As an assignment, Select various systems and observe the orbits.

|-
|| 13:46
|| Change the Initial settings and observe the changes in the orbits and Explain the observation.

|-
|| 13:54
|| Let us Summarise.

|-
|| 13:57
|| In this tutorial we have demonstrated, How to use '''Gravity and Orbits''' and '''My Solar System''', '''PhET simulations'''.

|-
|| 14:07
|| Using this '''simulations''' we have, Described the relation between Sun, Earth, Moon and Satellite.

|-
|| 04:15
|| Studied the effect of mass and distance on gravitational force.

|-
|| 14:20
|| Explained how gravity controls the motion of our solar system.

|-
|| 14:25
|| Identified the variables that affect the strength of gravity.

|-
|| 14:30
|| And Determined the gravitational force.

|-
|| 14:35
|| The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

|-
|| 14:44
|| The '''Spoken Tutorial Project''' team: conducts workshops using spoken tutorials and

gives certificates on passing online tests.

|-
|| 14:54
|| For more details, please write to us.

|-
|| 14:58
|| Please post your timed queries on this forum.

|-
|| 15:03
|| This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.

|-
||15:12
|| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.
|-
|| 15:25
|| This is Meenal Ghoderao from IIT Bombay.

Thank you for joining.
|-
|}

@@ Line 26: / Line 26: @@
 |-
 || 00:34
-|| To follow this tutorial, Learner should be familiar with topics in high school science.
+|| To follow this tutorial, learner should be familiar with topics in high school science.
 |-
 || 00:42
-|| Using these simulations we will -  Describe the relation between Sun, Earth, Moon and satellite.
+|| Using these simulations we will -
 |-
 || 00:51
-|| Study the effect of mass and distance on gravitational force.
+||2. Study the effect of mass and distance on gravitational force.
 |-
 || 00:56
-|| Explain how gravity controls the motion of our solar system.
+||3. Explain how gravity controls the motion of our solar system.
 |-
 ||01:02
-|| Identify the variables that affect the strength of gravity.
+||4. Identify the variables that affect the strength of gravity.
 |-
 || 01:08
-|| And determine the gravitational force.
+||5. And determine the gravitational force.
 |-
@@ Line 62: / Line 64: @@
 |-
 || 01:34
-|| This force of attraction is '''gravitational force'''.
+|| This force of attraction is gravitational force.
 |-
@@ Line 70: / Line 72: @@
 |-
 || 01:43
-|| Use the given link to download the simulation.
+|| Use the given link to download the '''simulation'''.
 |-
@@ Line 94: / Line 96: @@
 |-
 || 02:16
-|| The interface has two screens. '''Model'''
+|| The interface has two screens.
 '''To Scale'''.
@@ Line 170: / Line 174: @@
 |-
 || 03:43
-|| By default '''Sun and Earth''' system is selected.
+|| By default Sun and Earth system is selected.
 |-
@@ Line 182: / Line 186: @@
 |-
 || 03:57
-|| This circular motion is due to '''centripetal force'''.
+|| This circular motion is due to centripetal force.
 |-
 || 04:02
-|| '''Centripetal force''' causes change in acceleration and keeps the body moving along the circular path.
+|| Centripetal force, causes change in acceleration and keeps the body moving along the circular path.
 |-
@@ Line 202: / Line 206: @@
 |-
 || 04:25
-|| Notice that, Direction of Earth's velocity is perpendicular to Sun's Gravitational pull.
+|| Notice that, direction of Earth's velocity is perpendicular to Sun's gravitational pull.
 |-
@@ Line 226: / Line 230: @@
 |-
 || 05:04
-|| Earth takes '''365 days''' to complete one revolution.
+|| Earth takes 365 days to complete one revolution.
 |-
@@ Line 246: / Line 250: @@
 |-
 || 05:24
-|| Observe that, In the absence of '''Gravity''', Earth files off along a straight line.
+|| Observe that, In the absence of Gravity, Earth files off along a straight line.
 |-
@@ Line 294: / Line 298: @@
 |-
 || 06:21
-|| Here sun is not at the center of the orbit.
+|| Here sun is not at the centre of the orbit.
 |-
@@ Line 322: / Line 326: @@
 |-
 || 06:53
-|| Observe that, Gravitational force decreases with increase in the distance between planet and sun.
+|| Observe that, gravitational force decreases with increase in the distance between planet and sun.
 |-
@@ Line 446: / Line 450: @@
 |-
 || 09:44
-|| '''Gravitational force''' is calculated by using following formula
+|| Gravitational force is calculated by using following formula
 where '''G''' is universal gravitation constant
@@ Line 554: / Line 558: @@
 |-
 || 12:28
-|| We see 3 colored objects planet, sun and comet.
+|| We see 3 coloured objects planet, sun and comet.
 |-
@@ Line 639: / Line 643: @@
 |-
 || 14:44
-|| The '''Spoken Tutorial Project''' team: conducts workshops using spoken tutorials and
+|| The Spoken Tutorial Project team: conducts workshops using spoken tutorials and
 gives certificates on passing online tests.

PhET/C3/Gravity-and-Solar-system/English-timed - Revision history

Sandhya.np14 at 09:43, 13 August 2018

Madhurig at 12:16, 8 August 2018

PoojaMoolya: Created page with " {|border=1 ||'''Time''' ||'''Narration''' |- || 00:01 || Welcome to this tutorial on '''Gravity and Solar System'''. |- || 00:06 || In this tutorial we will, Demonstrate..."