# 0.11 Phy1080: motion -- variable velocity and acceleration  (Page 17/19)

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Screen output

The text shown in Figure 13 should appear in the browser window when you open the html file in the browser.

Figure 13 . Screen output for Listing #5.
```Start Script On EarthArrow is at 89.9 feet at 1.00 seconds Arrow is at 89.9 feet at 5.21 secondsOn the Moon Arrow is at 89.9 feet at 0.86 secondsArrow is at 89.9 feet at 36.33 seconds End Script```

A function named getRoots

The quadratic formula isn't very complicated, but it is fairly tedious and easy to type incorrectly. Therefore, I decided to encapsulate it in afunction that we can copy into future scripts saving us the need to type it correctly in the future.

Listing 5 begins with the definition of a function named getRoots that receives the parameters a, b, and c, and returns the roots of the quadraticequation in a two-element array.

Real or imaginary roots

The roots of a quadratic equation can be either real or imaginary. If the roots are imaginary, this function simply returns NaN (not a number) for eachroot.

The parameters of the problem

Following the definition of the getRoots function, Listing 5 declares and initializes several variables to establish the parameters of the problem, such as the accelerationof gravity on the earth and moon, the initial velocity of the arrow, etc.

The computed height versus the target height

The target height for the problem is 89.9 feet. Note that the variable named d contains that value less the initial height of 6 feet. Thus, the script willfind the time at which the arrow has traveled 83.9 feet on the way up, and the time that it has traveled that same distance on the way back down.

The next three lines of code use the problem parameters to establish values for the standard coefficients of a quadratic equation, a, b, and c, as described above . Note that at this point in the script, the coefficient named a is based on the acceleration of gravity on earth. (Later, it will be changed to reflect the acceleration ofgravity on the moon.)

Get the roots of the quadratic equation

Then the script calls the getRoots function, passing a, b, and c as parameters, and stores the returned array containing the roots in the variablenamed roots .

Following that, the script extracts the roots from the array and displays them as shown by the text in the upper half of Figure 13 .

Repeat the process for the moon

Then Listing 5 sets the value of the coefficient named a to reflect theacceleration of gravity on the moon, repeats the process, and displays the results in the lower half of Figure 13 .

Note that the arrow reaches the target height somewhat quicker on the moon due to the lower acceleration of gravity, and takes much longer to arrive at thesame height on the way back down to the surface of the moon. Were we to create a chart similar to Figure 4 for the moon, we would see that the arrow goes much higher before turning around and falling back to the surface of the moon.

## Other useful equations

You have learned how to use the following equation to solve various physics problems involving motion in a straight line with uniform acceleration so far inthis module.

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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