# 2.7 Game 2302-0370 motion -- uniform and relative velocity  (Page 8/11)

 Page 8 / 11

resultant[0].toFixed(2)

In this case, the "[0]" means to retrieve the value stored in thearray element identified by the index value 0.

Once that value has been retrieved, the built-in toFixed method is called, passing the literal value 2 as a parameter, to format the valueso that it will be displayed with two digits to the right of the decimal point.

Figure 5 shows that value displayed in the line of text that reads:

Velocity magnitude = 3.00 miles/hour

(Note that very few of the values that I display in these modules comply with the rules for decimal digits and significant figures that I explained in anearlier module.)

A partial solution to the problem

A partial answer to the question posed for this exercise is that the magnitude of the man's overall velocity with respect to the ground is 3 milesper hour as shown in Figure 5 .

The rest of the solution

The next statement in Listing 3 uses a similar syntax to retrieve the value from the second element in the array object (the element with an index value of1) and to display it as

Velocity angle = 0.00 degrees

as shown in Figure 5 .

This means that the man is moving due east (the same direction that the train is moving) with a velocity of 3 miles per hour with reference to the ground.

Analysis of the results

Now I will tell you why I used a strange walking speed (2.933 feet per second) for the man. As it turns out, this is very close to 2 miles per hour, and Iwanted the man to have a walking speed that would result in simple numeric results.

Let's review the problem

The train is moving east with a uniform velocity of 1 mile per hour relative to the ground.

The man is moving east with a uniform velocity of 2 miles per hour (2.933 feet per second) relative to the train.

What is the man's velocity relative to the ground?

The algebraic sum of the magnitudes

Because the man and the train are both moving along the same straight line, and the man's velocity is stated relative to the train, the magnitude of the man's velocityrelative to the ground is the algebraic sum of the magnitudes of the two velocities. Because they are both moving in the same direction, that algebraicsum is additive.

An analysis of the velocities

The train is moving 1 mile per hour with reference to the ground, and the man is moving 2 miles per hour with reference to the train (along the same line andin the same direction as the train). Therefore, the man is moving 1+2=3 miles per hour with reference to the ground.

This means that an observer standing on the ground at a point on a line perpendicular to the train would perceive the man to be moving to the to theright with a velocity of 3 miles per hour (assuming that the train is moving to the right).

A zero-degree angle is not required

Note that it isn't necessary that the train and the man be moving at an angle of zero degrees (east). The magnitude of the result would be the same regardless of thedirection that they are moving provided they are moving along the same straight line.

We will specify a different common direction for the train and the man in the next exercise.

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
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
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!