# 0.8 Phy1050: units and dimensional analysis  (Page 10/11)

 Page 10 / 11

Screen output

When you open the html file in your browser, the text shown in Figure 6 should appear in your browser window.

Figure 6 . Screen output for Listing #2.
```At 10 seconds: distance traveled = -1609 feetheight = 8391 feet At 20 seconds:distance traveled = -6435 feet height = 3565 feetThe End```

As you can see from Figure 6 , after ten seconds, the rock will have traveled a distance of -1609 feet. (The minus sign indicates downwardmotion.)

Adding this value to the initial height of 10000 feet produces a value of 8391 for the height of the rock at the end of 10 seconds.

Similarly, Figure 6 gives us 3565 for the height of the rock at 20 seconds.

Analysis of the code

The code in Listing 2 begins by defining a function that computes and returns the distance traveled for a rock falling toward the earth for a given timeinterval since release assuming that the initial velocity was zero (the rock was simply dropped).

This function implements the equation shown earlier, and expects to receive the time as an input parameter. It returns thedistance traveled during that time interval.

Note that the interaction of units is shown in the comments with the result that the returned value is in feet.

Call the function twice in succession

Then the code calls that function twice in succession for two different timeintervals (10 seconds and 20 seconds) to determine the distance traveled during each time interval.

In both cases, the distance traveled is added to the initial height of 10000 feet to determine the height of the rock at the end of the time interval.

Also, in both cases, the time interval, the distance traveled, and the resulting height of the rock above the ground are displayed as shown in Figure 6 .

Note again that in all cases, the interactions of the various units are shown in the comments.

## A plotting exercise

Let's do another exercise and this time plot the results.

Please prepare your plot board to plot a curve defined by several points. Interpret the grid lines such that you can plot values ranging from 0 to 10000feet on the vertical axis and you can plot values ranging from 0 to 30 seconds on the horizontal axis.

A tactile graph

If you have an assistant who will download the zip file named Phy1050.zip , extract the file named Phy1050a1.svg, and use that file to create a tactilegraph as described in the module named Manual Creation of Tactile Graphics . You can explore the tactile graph instead. Regardless, you should write the script and examine the printed output as described in thefollowing paragraphs.

JavaScript code

Copy the code from Listing 3 into an html file and open it in your browser.

Listing 3 . A plotting exercise.
```<!-- File JavaScript03.html --<<html<<body<<script language="JavaScript1.3"<//Function to compute free-fall distance for a given time // interval in seconds.function distance(time){ var g = -32.174; //acceleration of gravity in feet/sec^2var d = 0.5 * g * time * time;//(feet/sec^2)*sec^2 = feet return new Number(d.toFixed(0));}//end function //Compute the height of the rock every two seconds from// release until the rock hits the ground. var t = 0;//secondswhile(t<= 30){ d = distance(t);//distance traveled in feeth = 10000 + d;//height in feet//Don't allow the height to go negative (underground) if(h<0){ h = 0;}//end if//Display time and height at current time. document.write("time = " + t +" height = " + h + "<br/<"); t = t + 2;}//end while document.write("</br<The End")</script<</body<</html<```

#### Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
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
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
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
how did you get the value of 2000N.What calculations are needed to arrive at it
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