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

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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.

Contributors and Content Editors

PoojaMoolya