View source for Apps-On-Physics/C2/Simple-Machines/English




{|border=1
|| '''Visual Cue'''
|| '''Narration'''
|-

||'''Slide Number 1 '''
'''Title Slide'''
||Welcome to this spoken tutorial on '''Simple Machines'''.
|-
||'''Slide Number 2 '''

'''Learning objective '''
||In this tutorial we will demonstrate,

Pulley system

Lever Principle Apps.
|-
||'''Slide Number 3'''

'''System Requirements'''
||Here I am using,

Ubuntu Linux OS version 16.04

Firefox Web Browser version 62.0.3
|-
||'''Slide Number 4'''

'''Pre-requisites'''
||To follow this tutorial, 
learner should be familiar with topics in basic physics.
|-
||'''Slide Number 5'''

'''Learning Goals'''
||Using these '''Apps''' we will,

* Show how a pulley system works.
* Calculate the necessary force to pull the load.
* Show the working of a lever.
* Explain how to achieve a balance condition.

|-
||'''Slide Number 6'''

'''Pulley'''

A pulley is a simple machine that is used to lift heavy objects.

We can either use a single pulley or a combination of pulleys.


For example pulleys can be used in 

wells, escalators, rock climbing, flag poles and others.



||First we will define a pulley.

A pulley is a simple machine that is used to lift heavy objects.


We can either use a single pulley or a combination of pulleys.


For example pulleys can be used in 

wells, escalators, rock climbing, flag poles and others.
|-
||'''Slide Number 7'''

Link for '''Apps on physics''' .

'''https://www.walter-fendt.de/html5/phen/'''



||Use the given link to download the '''Apps'''.

'''https://www.walter-fendt.de/html5/phen/'''



|-
||Point to the file in the downloads folder.
||I have already downloaded '''Apps on Physics '''to my '''Downloads''' folder.
|-
||Point to '''html5phen''' folder in the '''Downloads '''folder.
||After downloading, '''html5phen''' folder appears in the '''Downloads '''folder.



|-
||Double-click on '''html5phen''' folder.


Point to the '''ph''' and '''phen''' folders.
||Double-click on '''html5phen''' folder.


We see two folders namely '''ph''' and '''phen'''.

|-
||Double-click on '''phen '''folder.


Point to '''Apps''' in '''java script'''  and '''htm '''format. 
||Now double-click on the '''phen '''folder.


In this folder, we see the '''Apps''' in '''java script ''' and '''htm '''format.
|-
||Point to the '''htm''' formats '''Apps'''.
||We will use the Apps with '''htm file''' format.



|-
||Point to '''Pulley system App'''.
||To open the Pulley system app, press '''Ctrl+F''' keys  simultaneously.

In the search bar type '''Pulley system'''. 
|-
||Right click on '''pulleysystem_en.htm''' file.


Select the option '''Open With Firefox web Browser''' option.


Cursor on the '''App'''.
||Right click on '''pulleysystem_en.htm ''' file.


Select the option '''Open With Firefox web Browser'''.


'''Pulley System App''' opens in the browser.
|-
||Point to the '''App''' interface.

Move the cursor to the yellow panel.

Move the cursor to the green panel.
||The '''App''' interface opens with two panels.

A yellow panel with a pulley system and

A green panel to change and display parameters.
|-
||Move the cursor on the load – pulley-rope.
||In the yellow panel, notice that a load is attached to the pulley with the help of a rope.
|-
||Point to the '''Springscale.'''
||We can either raise or lower the load using a '''Springscale. '''
|-
||Show the movement of the '''Springscale''' by the pressed mouse.


Point to the values in the right panel.
||Click and drag the mouse to raise or lower the load.

Observe that there is no change in the value on the right panel.

This is because the necessary force required to drag the load remains the same.
|-
||Click on drop down list to show the numbers of pulleys
||On the top of the green panel you can see a drop down list of pulleys.

List has 2, 4, and 6 pulley systems.
|-
||Point to the '''Weight'''.


Edit and show 1 value
||The weight of the load is displayed in the white box.


The default weight of the load is 14 '''Newton'''.


We can change the value of the weight from 1 '''Newton''' to 40 '''Newton'''.
|-
||Move the cursor to show the Weight of the loose pulleys.
||We can change the '''Weight of the loose pulley '''in this box. 
|-
|| Point to the black pulleys.
|| This is the total weight of the 4 pulleys.
|-
||Point to show '''Necessary force'''.
||The '''Necessary force''' used to lift the load is calculated using the '''App'''.
|-
||

Point to '''Springscale''' and

'''Force vectors'''.
||At the bottom of the green panel we have '''Springscale''' and '''Force vectors''' radio buttons.


By default '''Springscale''' is selected.
|-
||cursor on the interface

||Let us demonstrate the working of the pulley.
|-
||Point to the load.

Point to the 4 sections of the rope. 

Point to '''Necessary force'''.
||Observe that weight of 20 '''Newton''' is hanging from the 4 pulley sections of the rope.

Each section of the rope has one fourth of the total weight.

In the '''App''' force required to raise the weight in  air is calculated.
|-
||'''Slide Number 8'''

'''Necessary force'''

'''F= (W<sub>l</sub>+ W<sub>p</sub>)/4'''

'''W<sub>l</sub>''' is '''Weight of the load'''.

'''W<sub>p</sub>''' is '''Weight of the loose pulley'''.
||The '''Necessary force''' is calculated using  formula.

'''F= (W<sub>l</sub>+ W<sub>p</sub>)/4'''

'''W<sub>l</sub>''' is '''weight of the load'''.

'''W<sub>p</sub> '''is '''weight of the loose pulley'''.
|-
||Edit the '''Weight of the loose pulley to 20 '''Newton'''.

Point to '''Necessary force'''
||Now change the '''Weight of the loose pulley''' to 20 '''Newton'''.

Observe that the '''Necessary force''' is changed to  10 '''Newton'''.
|-
||Change the '''Weight''' of the load to 30 '''Newton'''.
||Next change the weight of the load to 30 '''Newton'''.
|-
||

Point to the '''Weight of the loose pulley'''.

Highlight the last line from the '''App'''.
||observe that the '''weight of the loose pulley''' has changed to 10 '''Newton'''.

This is because the '''Springscale’s''' limit is 10 '''Newton'''.

Values more than 10 '''Newton''' are automatically changed.

|-
||'''Slide Number 9'''

'''Assignment'''

Change the weight of the load to 25 N and weight of the loose pulley to 10 N. Calculate the necessary force and verify your answer from the App. 

||As an assignment,

Change the weight of the load to 25 N and weight of the loose pulley to 10 N. 
Calculate the necessary force and verify your answer from the App. 

|-
||To open '''Lever Principle App''' right-click on '''lever_en.htm''' file  and '''Open With''' '''Firefox Web Browser'''.
||Next we will move on to '''Lever Principle App'''.

To open '''Lever Principle App''' right-click on '''lever_en.htm'''  file and '''Open With Firefox Web Browser'''.
|-
||Point to the screen(highlight the sentence from the App.)
||This '''App''' shows a symmetrical lever with some mass pieces.

Each mass piece weighs 1 '''Newton'''.
|-
||Scroll down to show the lever principle.
||At the bottom of the interface '''Lever Principle ''' is defined.

A lever is in balance if the total left side torque is equal to the total right side torque.
|-
||Scroll up to see the '''App'''.


Point to the lever arm.
||Observe that the lever arm is shown by green and orange rectangles.

Length of each rectangle is 0.10 '''m'''.
|-
||Point to the torque measured.
||At the bottom left of the screen torque is calculated.
|-
||'''Slide Number 10'''

'''Torque'''

Torque is the twisting force that tends to cause a rotation.

The point where the object rotates is aixs of rotation.
||Torque is the twisting force that tends to cause a rotation.

The point where the object rotates is the axis of rotation.
|-
||Point to the fulcrum.
||In the '''App''' fulcrum is the axis of rotation.
|-
||'''Slide Number 11'''

'''Torque'''

'''(tau) τ <nowiki>= F x r</nowiki>⟂'''

'''F''' is a force applied by the load.

'''r'''⟂ is a perpendicular distance from the fulcrum.
||We can calculate the torque using the formula.

'''(tau)τ <nowiki>= F x r</nowiki>⟂'''(perpendicular).

|-
||Point to green and orange rectangles.
||Green and orange rectangles indicate perpendicular distances.
|-
||Remove one weight from the left side of the fulcrum.
||We can change the hanging weight by clicking and holding the mouse.
|-
||Point to fulcrum.


Move the cursor to show the calculations.
||Observe that, the lever is unbalanced.


This is because torque on both the sides is not same.
|-
||Point to 0.9 Nm.
||Notice that the value of left side torque is reduced to '''0.9 Nm'''

'''(Newton-meter)'''.
|-
||Cursor on the interface.

||What happens when hanging weights are removed from both the sides.
|-
||Point to the left side of the fulcrum.
||Let us hang the weights at different distances to the left of the fulcrum.
|-
||Click and hold the mouse to add one weight on the third rectangle.
||Click and hold the mouse to add one weight on the third rectangle.
|-
||Add two weights on the fourth rectangle.

One weight on the fifth rectangle.
||Add two weights on the fourth rectangle.

And one weight on the fifth rectangle.
|-
||Point to the lever.
||Observe that the lever is now unbalanced.
|-
||Point to the right side.
||Let us add weights to the right side of the fulcrum to balance the lever.
|-
||Use pressed mouse to add the weights from 

right to 1st rectangle.
||Click and hold the mouse to add one weight to the first rectangle.
|-
||Hang the weight to 3rd, 4th, and 5th rectangles.
||Continue to add weights to third, fourth and fifth rectangles.
|-
||Point to the lever.
||Notice that the lever is now balanced.
|-
||'''Slide Number 12'''

'''Assignment'''

On the same side of the fulcrum, if a block weighing 5 N is kept at 0.5 m and a block weighing 3 N is kept at 0.6 m, then how far a block weighing 7 N should be kept on the other side of the fulcrum to achieve a balance condition.

||As an assignment solve this numerical. 

|-
||
||Let us summarize
|-
||'''Slide Number 13'''

'''Summary'''
||Using these '''Apps''' we have 

* Observed how a pulley system works.
* Calculated the necessary force to pull the load.
* Observed the working of a lever.
* Explained how to achieve a balance condition.

|-
|| '''Slide Number 14'''

'''Acknowledgement'''

These Apps are created by Walter-fendt and his team.

|| These Apps are created by Walter-fendt and his team.



|-
||

'''Slide Number 15'''

'''About Spoken Tutorial project.'''
The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

||The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.
|-
||'''Slide Number 16'''

'''Spoken Tutorial workshops.'''

'''Spoken Tutorial Project team,

conducts workshops using spoken tutorials 

and gives certificates on passing online tests.

For more details, please write to us.
||'''Spoken Tutorial Project team,

conducts workshops using spoken tutorials 

and gives certificates on passing online tests.

For more details, please write to us.

|-
||'''Slide Number 17'''

'''Forum for specific questions:'''

Do you have questions in THIS Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question. Explain your question briefly

Someone from our team will answer them.


||Do you have questions in THIS Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question. Explain your question briefly

Someone from our team will answer them.

|-
||'''Slide Number 18'''

'''Forum for specific questions:'''

The Spoken Tutorial forum is for specific questions on this tutorial

Please do not post unrelated and general questions on them

This will help reduce the clutter

With less clutter, we can use these discussion as instructional material
||The Spoken Tutorial forum is for specific questions on this tutorial

Please do not post unrelated and general questions on them

This will help reduce the clutter

With less clutter, we can use these discussion as instructional material.

|-
||'''Slide Number 19'''

'''Acknowledgement'''

||Spoken Tutorial Project is funded by MHRD, Government of India.
|-
||
||This is Himanshi Karwanje from IIT-Bombay. 

Thank you for joining.
|-
|}