Apps-On-Physics/C2/Linear-Motion/English-timed

Time	Narration
00:01	Welcome to the Spoken Tutorial on Linear Motion.
00:05	In this tutorial we will, Verify Newton's first law of motion using constant acceleration simulation.
00:13	Calculate position and velocity of a car using equations of motion.
00:19	Verify Newton's second law of motion using air track glider simulation.
00:26	Here I am using, Ubuntu Linux OS version 16.04. Firefox Web Browser version 62.0.3.
00:39	To follow this tutorial, learner should be familiar with Apps on Physics.
00:46	For the pre-requisites tutorials please visit this site.
00:51	Use the given link to download the App.
00:55	I have already downloaded Apps on Physics to my Downloads folder.
01:00	In this tutorial we will use, Motion with constant Acceleration and Newton's Second Law Experiment Apps
01:10	Double-click on html5phen folder. Double-click on the phen folder.
01:17	To open Motion with Constant Acceleration, press Ctrl + F keys simultaneously.
01:24	In the search bar type acceleration.
01:28	Right click on acceleration_en.htm file.
01:33	Select the option Open With Firefox web Browser.
01:38	Motion with constant Acceleration App opens in the browser.
01:43	Interface has two panels.
01:46	Green control panel contains text fields.
01:50	Here we can edit Initial position , Initial velocity and Acceleration.
01:58	At the bottom of the green panel there are two radio buttons.
02:03	Show velocity vector and Show acceleration vector. By default Show velocity vector is selected.
02:13	On the yellow panel we have three digital clocks. They show the elapsed time.
02:20	Here we can see a green and red coloured barriers.
02:25	Click on Start button.
02:28	Click the Slow motion check-box.
02:31	Observe that a car starts to move with a constant acceleration.
02:37	The default value for Acceleration is 1 m/s2 (meter per second square).
02:42	When the car crosses the green barrier with its front bumper, green digital clock stops.
02:49	Similarly when the car crosses the red barrier, the red digital clock stops.
02:55	Notice that car has moved out of the screen, but it is still in motion.
03:01	This is indicated by grey digital clock.
03:05	This clock shows the instantaneous time of the moving car.
03:10	Observe that, the values of x and v are changing continuously.
03:16	It means that the car is in uniform motion.
03:20	And it will continue to be in motion until an external force is applied. This is due to Newton's first law of motion.
03:30	Click on the Pause button and uncheck the Slow motion check-box.
03:36	Let’s assume that by clicking Pause button we have applied an external force on the car.
03:43	Notice that the grey digital clock has stopped.
03:47	It means that car has stopped moving.
03:51	Click on the Reset button.
03:54	Let's change the Initial position to 5 meter and press Enter.
03:59	Change the Initial velocity to 5 m/s (meter per second) and press Enter.
04:04	And value of Acceleration to 2 m/s2 (meter per second square) and press Enter.
04:10	Observe the Position v/s time and Velocity v/s time graphs.
04:15	The red point in the Position v/s time graph has shifted from 0 meter to 5 meter.
04:22	The pink point in the Velocity v/s time graph has shifted from 0 m/s to 5 m/s.
04:30	Notice the shift in blue point in Acceleration v/s time graph.
04:35	Click on the Start button.
04:38	And then click on the Pause button when car touches the red barrier.
04:43	Observe that the pink colored vector shows the direction of velocity.
04:48	Now let us study the variations in each graph.
04:52	Observe the Acceleration v/s time graph.
04:56	It shows a straight line parallel to the time axis.
05:00	As time changes acceleration remains constant.
05:05	Observe the Velocity v/s time graph. Note that velocity increases linearly with time.
05:12	Look at the Position v/s time graph.
05:16	This graph is exponentially increasing, due to the change in position and velocity of the car.
05:23	Let us verify the values of position and velocity using equations of motion.
05:30	Here are the Equations of motion.
05:33	We will note the measured and calculated values in the table.
05:39	Next we will use both green and red barrier to measure position and velocity.
05:45	Click and drag the green barrier to 15 meter.
05:49	Similarly drag the red barrier to 40 meter.
05:53	Click on the Start button and then Pause when it touches the green barrier.
05:59	Note that the App has measured the values of position and velocity.
06:05	Let us calculate velocity using the first equation of motion.
06:11	Substitute the values of acceleration, time and initial velocity shown in the App in the equation.
06:19	8.06 m/s is the calculated value of the velocity.
06:25	Let us calculate the position using the second equation of motion.
06:30	Similarly substitute the values shown in the App.
06:34	14.99 meter is the calculated value of the position.
06:40	Observe that the values of position and velocity are approximately equal to the measured values.
06:48	Note the calculated and measured values in the table.
06:52	As an assignment Measure the position and velocity when the car reaches the red barrier.
06:59	Calculate the values using Equations of motion.
07:03	Complete the table and compare your answers with the ones shown in the App.
07:09	Now we will explore the next App.
07:12	To open Newton's Second Law Experiment App, Right click on the newtonlaw2_en.htm file and Open With Firefox Web Browser.
07:24	Using this App we will verify the Newton's second law.
07:29	The App opens with air track glider setup.
07:33	The screen shows a wagon on the air track.
07:37	Here digital clock is used to record the time when wagon crosses the LB. LB is the light barrier.
07:46	The graph records position v/s time data.
07:51	In the green control panel we can vary Mass of the wagon , Hanging mass and Coefficient of friction.
08:00	The default Mass of the wagon is 100 g. It can take values from 1 g to 1000 g
08:09	Scroll down the screen.
08:12	Here we have the formula used in this experiment.
08:16	By default, motion with constant acceleration is used in the App.
08:22	Click on the Start button.
08:25	This button is a toggle for Start and Record data.
08:29	Observe that the hanging mass pulls the wagon downwards.
08:34	Default value of the Hanging mass is 1 gram, it takes values from 1 gram to 100 grams.
08:42	Here digital clock notes the time when the wagon crosses the LB.
08:47	The distance from the start to LB is shown as 0.5 meter.
08:53	The App has calculated the acceleration using the formula 2s/t2(2s upon t square).
08:59	The calculated value of acceleration is 0.097 m/s2.
09:06	Click on the Reset button.
09:09	Click and drag the LB to the left on second black rectangle.
09:14	Click on the Start button.
09:17	Notice that here also the value of acceleration is 0.097 m/s2.
09:25	Click on the Record data button. The values are recorded in the Data box.
09:32	Observe that the Diagram button is inactive.
09:36	It becomes active when at least four values are recorded in the Data box.
09:42	Again click and drag the LB to second green rectangle.
09:47	Click on the Start button and then click on Record data button.
09:53	Similarly take four more readings for distance and time and record in the Data box.
10:00	In the Data box, readings of six different distances have been recorded.
10:06	Observe the plotted points for position and time in the graph.
10:11	Diagram button is now active. Click on the Diagram button to plot the graph.
10:18	An exponential graph appears on the screen.
10:22	Notice that, acceleration remains same for all the distances.
10:27	It means that change in distance does not change the acceleration.
10:33	According to Newton's second law the acceleration depends on the mass of the wagon.
10:39	Click on the Reset button.
10:42	Now change the Mass of the wagon to 300 g.
10:46	Click on Start button.
10:49	Notice the change in the acceleration.
10:52	The value of acceleration has changed to 0.033 m/s2.
10:59	Click on the Reset button.
11:02	Now let us change the value of Hanging mass to 4 g.
11:07	Click on Start button.
11:11	Notice the change in the acceleration. The value of acceleration has changed to 0.129 m/s2.
11:21	Recall that acceleration depends on mass of the wagon and the hanging mass.
11:28	Let us make a tabular column to note the values.
11:33	As an assignment Change the values of mass of the wagon and note the changes in acceleration.
11:41	For each value of mass of the wagon change the value of the Hanging mass.
11:47	Observe the difference in the acceleration.
11:51	Your completed assignment should look like this.
11:56	Let us summarize
11:58	Using these Apps we have, Verified Newton's first law of motion using constant acceleration simulation.
12:06	Calculated position and velocity of a car using equations of motion.
12:12	Verified Newton's second law of motion using air track glider simulation.
12:19	These Apps were created by Walter-fendt and his team.
12:24	The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
12:32	The Spoken Tutorial Project team, conducts workshops and gives certificates. For more details, please write to us.
12:41	Please post your timed queries on this forum.
12:45	Spoken Tutorial Project is funded by, MHRD, Government of India.
12:50	This is Himanshi Karwanje from IIT-Bombay. Thank you for joining.

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PoojaMoolya