PhET/C3/Projectile-Motion/English

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Time Narration
Slide Number 1

Title Slide

Welcome to this tutorial on Projectile motion.
Slide Number 2

Learning Objectives

In this tutorial we will demonstrate,

Projectile Motion PhET simulation.

Slide Number 3

Pre-requisites

To follow this tutorial,

Learner should be familiar with topics in high school physics.

Slide Number 4

System Requirement

Here I am using,

Ubuntu Linux OS version 14.04

Java version 1.7

Firefox Web Browser version 53.02.2.

Slide Number 5

Learning Goals

Using this simulation we will,


Determine how each parameter affects the trajectory of an object

Estimate where an object will land, given its initial conditions.

Determine how horizontal and vertical motion of a projectile are independent.

Slide Number 6

Learning Goals

Investigate the variables that affect the drag force.

Examine the effect of drag force on the velocity and acceleration.

Slide Number 7

Definition of a Projectile

Let us define a projectile.

A projectile is any object that is fired, pitched or thrown.

The path of the projectile is called its trajectory.

Slide Number 8

Projectile Motion

Projectile motion is a form of motion,

in which a projectile is thrown near the Earth's surface.

Slide Number 9

Effect of Gravity on Projectile

A projectile moves along a curved path under the action of gravity.

Gravity is the downward force acting on a projectile.

Gravity influences its vertical motion and causes the parabolic trajectory.

Slide Number 10

Examples of Projectile motion

Some examples of projectile motion are,

A baseball that has been thrown.

A bullet that is fired from a gun or rifle.

Slide Number 11

Link for PhET simulation


http://phet.colorado.edu

Use the given link to download the simulation.


http://phet.colorado.edu

Point to the file in Downloads folder. I have already downloaded Projectile Motion PhET simulation to my Downloads folder.
Right click on projectile-motion_en.html file.

Select Open With Firefox Web Browser option.

To open the simulation, right click on projectile-motion_en.html file.

Select the option Open With Firefox Web Browser.

Cursor on the interface. This is the interface of Projectile Motion PhET simulation.
Point to each screen. The interface has four screens,

Intro

Vectors

Drag

Lab.

Click on Intro screen. Click on Intro screen.

Using this screen let's study the factors affecting a projectile’s trajectory.

Point to the mounted cannon on the pedestal. Intro screen has a cannon mounted on a pedestal.
Point to the Height label.

Adjust the height by dragging.

Default height of the pedestal is 10 m.

Height label disappears when height is adjusted.

We can change the height of the pedestal between 0 to 15 m.

Click on Reset button. Click on Reset button to reset the simulation.
Move the cursor on to cannon angle.

Drag the cannon to change the angle.

By default, cannon's angle is at 0 degrees.

Cannon's angle can be changed from - 90 degrees to 90 degrees(-90 to 90).

Drag Cannon's angle to zero degrees.

Move the cursor on the Initial Speed slider. At the bottom of the screen we have,

a slider to change Initial Speed.

Point to Eraser button. Yellow Eraser icon to erase the trajectory.
Point to Launch projectile button. Red Launch Projectile icon to launch the projectile.
Point to Play/Pause.

Point to Step button.

Play/Pause and Step buttons.
Point to Normal and Slow Point to radio buttons. Normal and Slow radio buttons to change animation speed.
Point to Zoom in and Zoom out buttons. At the top left corner we have Zoom in and Zoom out buttons to zoom the view.
Click and drag the probe.

Click and drag the measuring tape.

On the top right corner we have a white box.

It contains a probe and a measuring tape.

Drag the probe. Probe is used to measure Time, Range and Height of the trajectory.
Point to the drop down list.

Point to Pumpkin.

A drop down list is provided to select the projectiles.

By default Pumpkin is selected as a projectile.

Point Mass and Diameter. Mass and Diameter of the selected projectile is displayed below the list.
Point to Air Resistance check box. Next we have a check box to introduce Air Resistance with Drag Coefficient.
Point to Total and Component check boxes . Then we have Velocity Vectors and Acceleration Vectors check boxes.
Click on the drop down list of projectiles.

Select Human projectile.

Let us select Human projectile from the list.

Observe the displayed Mass and Diameter of the Human projectile.

Click on Launch icon.

Move the cursor over the trajectory.

Click on red Launch icon

Observe the trajectory.

Drag to change cannon's angle to 10 degrees.

Click on Launch icon.

Next we will change cannon's angle to 10 degrees.

Launch the projectile.

Move the cursor over the trajectory. Observe projectile's trajectory as we change cannon's angle.

Highest point is shown in green colour.

Drag and place the probe.

Point to the point.

Drag and place the probe on highest point of the trajectory.

Note the Time, Range and Height at the highest point.

Slide Number 12

Tabular Column

Let us make tabular column for Cannon's Angle, Time Range and Height.

I will entered the values for 10 degrees angle.

Drag the probe. Drag the probe back to its place.
Drag to change cannon's angle to 20 degrees. Similarly I will change the cannon's angle to 20 degrees.

Launch the projectile and observe the trajectory.

Drag and place the probe on highest point.

Note the values in the table.

Place the probe on highest point of the trajectory.

Note the values of Time, Range and Height in the table.

I have entered the values in the table.

Slide Number 13

Assignment '

As an assignment,

Change the values of cannon's angle and complete the tabular column.

Click on Rest button. Click on Reset button to reset the simulation.
Click on Launch icon. Launch the projectile and observe the trajectory.
Point to the target on the base line.

Drag the target on the base line.

Adjust the target on the base line so that projectile falls on the target.
Click on Launch icon.

Point to the stars.

Launch the projectile and observe the trajectory.

Observe the stars as the projectile hits the target.

Drag the Initial Speed slider to 20 m/s >> launch the projectile

Cursor on the trajectory.

By default the slider is at 15 m/s Initial speed.

Initial Speed can be changed between 0 to 30 m/s.

Drag the Initial Speed slider to 20 m/s and launch the projectile.

Notice that, projectile moves faster and falls at a greater distance on the base line.

Click on Slow radio button.

Cursor on the trajectory.

Click on Slow radio button and launch the projectile.

Observe that, the projectile moves slowly.

Cursor on the trajectory. Notice that, Slow radio button slows down the animation speed.

It does not reduce the projectile's speed.

Click on Yellow eraser icon. Click on yellow eraser icon to erase the earlier trajectories.
Adjust cannon angle -10 >> initial speed to 25 m/s.

Launch the projectile.

Adjust the cannon's angle to -10 degrees and initial speed to 25 m/s.

Launch the projectile.

Observe the trajectory and distance covered.

Click on Velocity Vector's Total >> Component check boxes. Click on Vector's Total and Components check boxes.

Launch the projectile.

Cursor on the trajectory.

Uncheck the boxes.

Observe Velocity vector and its components on the trajectory.

Uncheck the boxes.

Click on Acceleration Vector's Total and Component check boxes Click on Acceleration Vector's Total and Components check boxes.

Launch the projectile and observe the trajectory.

Slide Number 14

Assignment

As an assignment,

Observe the projectile motion by

1. Selecting various projectiles

2. Changing initial speed and height of the pedestal.

Point to the Vectors screen .

Click on Vectors screen.

Next we will move on to Vectors screen.

Click on Vectors screen.

In this screen we will explore,

how velocity, acceleration and force are affected by air resistance.

Point to all the tools. Vectors screen has nearly same tools as in Intro screen.
Point to the height In this screen, pedestal's height is 0 metres and

cannon's angle is 80 degrees.

Drag the angle of cannon to 50 degree >> click on Launch icon. Change cannon's angle to 70 degrees and launch the projectile.
Point to Cannonball.

Drag Diameter and Mass sliders

Here we have only one projectile - Cannonball.

We can change the diameter and mass by dragging.

Click on Air Resistance check box.

Click on Launch icon.

Uncheck Air Resistance checkbox and launch the projectile.

Without air resistance projectile moves to a greater altitude and longer distance .

Point to the check boxes.

Velocity Vectors

Acceleration Vectors

Force Vectors.

Cursor on the trajectory.

Now click on the following check boxes-

Velocity Vectors

Acceleration Vectors

Force Vectors.

Launch the projectile.


You will see the vector components on the trajectory.

Cursor on Drag screen. Next we will move on to Drag screen.
Click on Drag screen. Click on Drag screen at the bottom of the interface.


In this screen we will,

Determine the factors that affect the drag force.

Observe the relation between drag force and velocity.

Point to Drag Coefficient and Altitude sliders. Additionally this screen has, Drag Coefficient and Altitude sliders.
Drag the Drag Coefficient slider to 0.04 . Let us move the Drag Coefficient slider to 0.04.

Notice the shape of the projectile.

It appears as a water drop.

Click on Launch icon.

Cursor on the trajectory.

Launch the projectile and observe the trajectory.

When the drag coefficient is small-

projectile travels to a greater altitude and greater distance.

Drag the probe.

Point to the values of Time, Range and height.

Drag and place the probe on the highest point.


Probe displays the Time, Range and height of the projectile.

Drag the probe back to its place.

Drag the Initial Speed slider to 14 m/s.

Drag Drag Coefficient to 0.45.

Click on Zoom button(+)

Click on Launch icon.

Change initial speed to 14 m/s and Drag Coefficient to 0.45


Click Zoom In button to zoom the view.

Launch the projectile and observe the trajectory.

Click on Zoom Out button. Click on Zoom Out button to show normal view.
Move the Drag coefficient slider to 0.50 value.

Drag the Altitude slider to 1700 m >> launch the projectile.

Now move the Drag coefficient slider to 0.50.

Change the initial speed to 24 m/s.


Drag the Altitude slider to 1700 m and launch the projectile.

Observe the trajectory.

Drag and place the measuring tape at the base line till the projectile touches the ground. Using measuring tape measure the distance covered by the projectile.
Point to Lab screen. Now we will move on to Lab screen.
Click on screen. Click on Lab screen.

In this screen we have a list of projectiles.

Point to Custom>>Select Custom.


Point to all the values.

Point to yellow coloured edit button.

Let us select the projectile as Custom.

Here we can change the values of,

Mass

Diameter

Gravity

Altitude and

Drag Coefficient manually.

Point to the yellow coloured edit button. Beside each attribute, notice an yellow coloured edit button.

These buttons are used to change the values manually.

Type 15 in the text box Now I will change Gravity value.

Click on edit button corresponding to Gravity.

A key pad opens.

Select 15 and click Enter.

Check the Air Resistance check box.

Click on Edit button.

Launch the projectile.

Check the Air Resistance check box.


Change the Altitude value to 2000 m using the edit button.


Launch the projectile and observe the trajectory.

Drag and place on the highest point. Drag and place the probe to measure the Highest point.
Slide Number 15

Assignment

As an assignment,

Change various custom parameters and launch the projectile.

Let us summarize.
In this tutorial, we have demonstrated,

Projectile Motion PhET simulation .

Slide Number 16

Summary

Using this simulation we have,

Determined how each parameter affects the trajectory of an object

Estimated where an object will land, given its initial conditions.

Determined how horizontal and vertical motion of a projectile are independent.

Investigated the variables that affect the drag force.

Examined the effect of drag force on the velocity and acceleration.

Slide Number 17

About Spoken Tutorial project

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

Please download and watch it.

Slide Number 18

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gives certificates on passing online tests.

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Slide Number 19

Forum for specific questions:

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

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Slide Number 20

Acknowledgements

This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
Slide Number 21

Acknowledgement

Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

This is Madhuri Ganapathi from IIT Bombay, singing off.

Thank you for joining.

Contributors and Content Editors

Madhurig