# 2.7 Game 2302-0370 motion -- uniform and relative velocity  (Page 6/11)

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Screen output

The text shown in Figure 5 should appear in your browser window when you open the html file in your browser.

Figure 5 . Screen output for Listing #3.
```Start Script Velocity magnitude = 3.00 miles/hourVelocity angle = 0.00 degrees End Script```

Analysis of the code

As before, the script begins by defining the getAngle function, which doesn't require further explanation.

The vectorSum function

As you can see from Listing 3 , this script contains a new function named vectorSum . The purpose of this function is to add two vectors, given the magnitude and angle (in degrees) for each vector asincoming parameters. (The function assumes that both incoming magnitude parameters are expressed in the same units.)

The need to add two vectors occurs so often in physics that I decided to encapsulate the capability into a function that we can copy into future scripts.That will relieve us of the need to rewrite the code each time we need that functionality.

Return an array object

The magnitude and the angle (in degrees) of the resultant vector is returned in a two-element array object, with the magnitude in the element at index 0 and the angle in the element at index 1.I will have a more to say about arrays shortly.

Note that this function calls the getAngle function, which must also be provided in the script.

Subtraction of vectors

The function can also be used to subtract one vector from another. To subtract one vector from another, simply add 180 degrees to the angle for the subtrahend vector before passing the angle to the function.

Although the function can only be used to add two vectors, it can be called repeatedly to add any number of vectors two at a time.

To use this function to add more than two vectors, add the first two vectors as normal. Then add the vector output from the function to the third vector, etc., until all of the vectors have been included in the sum.

The code in the vectorSum function

Most of the code in the function is the same as code that I have explained in earlier modules. However, there are a couple of lines of code that aredifferent.

The function begins with the following statement:

var vecResult = new Array(2);

The purpose of this statement is to create a two-element array object named vecResult .

What is an array object?

You can think of an array object as a software object containing pigeon holes into which you can store data and from which you can later retrieve that data. This particular arrayobject has two pigeon holes, and they are numbered 0 and 1.

This array object will be used as a container to return the magnitude and angle values for the resultant vector.

Can only return one item

A JavaScript function can only return one item. Up to this point in these modules, that item has consisted of a single numeric value, such as the anglevalue that is returned from the getAngle function.

However, the vectorSum function needs to return two different values. One way to do that is to put those two values in the pigeon holes of an array object andreturn that array object as the one item that can be returned.

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
Do somebody tell me a best nano engineering book for beginners?
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
what is nano technology
what is system testing?
preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
what is system testing
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
how did you get the value of 2000N.What calculations are needed to arrive at it
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