Apps-On-Physics/C2/Forces/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:01 | Welcome to the Spoken Tutorial on Forces. |
| 00:06 | In this tutorial we will, Find the resultant of forces using addition of vectors. |
| 00:13 | Achieve an equilibrium condition using parallelogram of forces. |
| 00:19 | Here I am using,
Ubuntu Linux OS version 16.04 |
| 00:26 | Firefox Web Browser version 62.0.3 |
| 00:31 | To follow this tutorial, learner should be familiar with Apps on Physics.
For the pre-requisites tutorials please visit this site. |
| 00:42 | Use the given link to download the Apps. |
| 00:46 | I have already downloaded Apps on Physics to my Downloads folder. |
| 00:51 | In this tutorial we will use,
Resultant of Forces and Equilibrium of Three Forces Apps. |
| 01:00 | Right click on resultant_en.htm file. |
| 01:05 | Select the option Open with Firefox Web Browser. |
| 01:10 | Resultant of Forces App opens.
You can open the App using any other browser. |
| 01:18 | This is the interface of Resultant of Forces. |
| 01:22 | By default, App shows two vectors drawn from a fixed point. |
| 01:27 | We can click and drag the vectors to change their magnitude and direction. |
| 01:33 | In the green control panel there is a drop-down to change the Number of forces. |
| 01:39 | From the drop-down we can change the values from 2 to 5.
By default 2 is selected. |
| 01:48 | Click on Find out resultant button. |
| 01:51 | Notice that the second vector translates parallel to itself.
It is attached to the head of the first vector. |
| 02:00 | Vectors are add using head to tail method. |
| 02:05 | Observe that the red vector, is the resultant vector formed by addition of two vectors. |
| 02:12 | It is drawn from the point of contact to the head of the second vector.
Addition of vectors follow triangle law of vectors. |
| 02:24 | Let us state triangle law of vector addition. |
| 02:28 | It states that, when two vectors are represented by two sides of a triangle with same magnitude and direction then the third side represents the resultant of vectors. |
| 02:43 | Click on Clear construction button to clear the resultant force. |
| 02:48 | From Number of forces drop-down select 5. |
| 02:52 | Click and drag the vectors to change their magnitude and direction. |
| 02:58 | Adjust the vectors to get equal magnitude for all vectors. |
| 03:04 | Then click on Find out resultant button. |
| 03:08 | Notice that each vector will get attached to the head of the previous vector. |
| 03:14 | The resultant is drawn, as its tail is joined to the tail of first vector and head to the head of last vector. |
| 03:24 | This represents polygon law of vector addition. |
| 03:29 | As an assignment
Change the number of forces to 3 and 4. |
| 03:35 | In each case, change the magnitude and direction. |
| 03:39 | Observe the resultant vectors and explain your observation. |
| 03:45 | Now let us explore Equilibrium of Three Forces. |
| 04:49 | To open the App right-click on equilibriumforces_en.htm file.
And Open With Firefox Web Browser. |
| 04:00 | This is the interface of Equilibrium of Three Forces. |
| 04:05 | Below the name a short description about how to use interface is given. |
| 04:11 | The hanging weights represent the forces acting on the knot. |
| 04:16 | The green panel shows Left, Right and Below forces. |
| 04:22 | These forces are acting on the knot to achieve an equilibrium condition. |
| 04:28 | Notice that each force must be smaller than the sum of other two forces. |
| 04:34 | App has measured the Left angle as 30 degrees and Right side angle as 56 degrees. |
| 04:44 | Let us define equilibrium of forces. |
| 04:47 | When all the forces acting on an object are balanced, then the object is said to be in a state of equilibrium. |
| 04:56 | By default Parallelogram of forces check-box is selected. |
| 05:01 | If we uncheck the box, angles formed will not be seen. |
| 05:06 | Press F5 key on the keyboard to get the default view. |
| 05:11 | Let us change the forces to 6 newton, 4 newton, and 8 newton. |
| 05:18 | Note that 6 is smaller than the sum of 8 and 4.
And note that 4 is smaller than the sum of 6 and 8. |
| 05:29 | Similarly 8 is smaller than the sum of 6 and 4. |
| 05:35 | This satisfies the above balance condition. |
| 05:39 | We can change the position of the pulleys using the mouse. |
| 05:44 | Choose 4 newton for Left, Right and Below forces. |
| 05:49 | Notice that for equal forces the Angle is always 60 degrees. |
| 05:55 | Use F5 button on the keyboard to refresh the App. |
| 05:59 | Change all the forces to 7 newton and observe the angles. |
| 06:05 | As an assignment - Try different combinations of forces to check the angles and equilibrium conditions.
Give an explanation. |
| 06:18 | Let us summarize. |
| 06:20 | Using these Apps we have,
Found the resultant of forces using addition of vectors. |
| 06:28 | Achieved an equilibrium condition using parallelogram of forces. |
| 06:34 | These Apps were created by Walter-fendt and his team. |
| 06:39 | The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. |
| 06:47 | The Spoken Tutorial Project team, conducts workshops and gives certificates.
For more details, please write to us. |
| 06:56 | Please post your timed queries in this forum. |
| 07:00 | Spoken Tutorial Project is funded by MHRD, Government of India. |
| 07:06 | This is Himanshi Karwanje from IIT-Bombay.
Thank you for joining. |
