# 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>```

what is variations in raman spectra for nanomaterials
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
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 did you get the value of 2000N.What calculations are needed to arrive at it
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!  By By  By By By By By By Qqq Qqq