# 2.7 Game 2302-0370 motion -- uniform and relative velocity  (Page 3/11)

 Page 3 / 11

Declare and initialize variables

The code in Listing 1 begins by declaring and initializing variables named velocity and distance . Note that the units are shown in the comments. I recommend that you always dothat in order to keep the units straight.

Perform the arithmetic

Then Listing 1 declares a variable named time and sets its value equal to distance divided by velocity . Once again, note the treatment of the units in the comments, showing that the units for the result of the division are hours.

Display the results

Finally, Listing 1 calls the document.write method several times in succession to display the results shown in Figure 1 .

## An exercise on average velocity

A hockey puck is struck by a player causing it to travel northeast at a uniform velocity of 50 feet per second for 15 feet, at which point it is struck by another player.

When struck by the second player, the direction of motion is changed to northwest witha uniform velocity of 60 feet per second.

It is stopped by a third player after traveling 20 feet in the northwest direction.

• What is the time required for the puck to complete each leg of its journey?
• What is the average velocity of the puck from the start to the end of its journey?

Vector diagram for the hockey puck

Figure 2 shows a vector diagram for the hockey puck.

Figure 2 - Vector diagram for the hockey puck.

Let's write a script to solve the problem

Please copy the code from Listing 2 into an html file and open it in your browser.

Listing 2 . An exercise on average velocity.

```<!---------------- File JavaScript02.html ---------------------><html><body><script language="JavaScript1.3">document.write("Start Script<br/>"); //The purpose of this function is to receive the adjacent// and opposite side values for a right triangle and to // return the angle in degrees in the correct quadrant.function getAngle(x,y){ if((x == 0)&&(y == 0)){ //Angle is indeterminate. Just return zero.return 0; }else if((x == 0)&&(y>0)){ //Avoid divide by zero denominator.return 90; }else if((x == 0)&&(y<0)){ //Avoid divide by zero denominator.return -90; }else if((x<0)&&(y>= 0)){ //Correct to second quadrantreturn Math.atan(y/x)*180/Math.PI + 180; }else if((x<0)&&(y<= 0)){ //Correct to third quadrantreturn Math.atan(y/x)*180/Math.PI + 180; }else{//First and fourth quadrants. No correction required. return Math.atan(y/x)*180/Math.PI;}//end else }//end function getAngle//Compute the time required to traverse each leg. Identify // the two legs as A and B.var vecAmag = 15;//displacement in feet var vecAang = 45;//displacement angle in degreesvar vecAvel = 50;//velocity magnitude in feet per second var timeA = vecAmag/vecAvel;//feet/(feet/second) = secondsvar vecBmag = 20;//displacement in feet var vecBang = 135;//displacement angle in degreesvar vecBvel = 60;//velocity magnitude in feet per second var timeB = vecBmag/vecBvel;//feet/(feet/second) = seconds//Compute the overall displacement //Compute the horizontal and vertical components// of each vector. var vecAh = vecAmag*Math.cos(vecAang*Math.PI/180);var vecAv = vecAmag*Math.sin(vecAang*Math.PI/180); var vecBh = vecBmag*Math.cos(vecBang*Math.PI/180);var vecBv = vecBmag*Math.sin(vecBang*Math.PI/180); //Compute the sums of the horizontal and vertical// components from the two vectors to get the // horizontal and vertical component of the// resultant vector. var vecResultH = vecAh + vecBh;var vecResultV = vecAv + vecBv; //Use the Pythagorean theorem to compute the magnitude of the// resultant vector in feet. var vecResultMag = Math.sqrt(Math.pow(vecResultH,2) +Math.pow(vecResultV,2)); //Compute the angle of the resultant vector in degrees.vecResultAng = getAngle(vecResultH,vecResultV); var totalTime = timeA + timeB;//secondsvar vecVelMag = vecResultMag/totalTime;//feet/second var vecVelAng = vecResultAng;//degreesdocument.write("Time for leg A = " + timeA.toFixed(2) + " seconds<br/>"); document.write("Time for leg B = " + timeB.toFixed(2) +" seconds<br/>"); document.write("Displacement magnitude = " +vecResultMag.toFixed(2) + " feet<br/>"); document.write("Displacement angle = " +vecResultAng.toFixed(2) + " degrees<br/>"); document.write("Total time = " + totalTime.toFixed(2) +" seconds<br/>"); document.write("Average velocity magnitude = " +vecVelMag.toFixed(2) + " feet/second<br/>"); document.write("Average velocity angle = " +vecVelAng.toFixed(2) + " degrees<br/>"); document.write("End Script");</script></body></html>```

#### Questions & Answers

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
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
Privacy Information Security Software Version 1.1a
Good
Berger describes sociologists as concerned with
Got questions? Join the online conversation and get instant answers!