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According to this author , there is no universally accepted name for the rate of change of jerk.

The algebraic sign of acceleration

When the velocity of a moving object increases, that is viewed as positive acceleration. When the velocity of the object decreases, that is viewed asnegative acceleration.

Uniform or variable acceleration

Acceleration may be uniform or variable. It is uniform only if equal changes in velocity occur in equal intervals of time.

A vector quantity

Acceleration has both direction and magnitude. Therefore, acceleration is a vector quantity.

The units for acceleration

The above definition for acceleration leads to some interesting units for acceleration. For example, consider a situation in whichthe velocity of an object changes by 5 feet/second in a one-second time interval. Writing this as an algebraic expression gives us

(5 feet/second)/second

Multiplying the numerator and the denominator of the fraction by 1/second gives us

5 feet/(second*second)

This is often written as

5 feet/second^2

which is pronounced five feet per second squared.

The acceleration of gravity

The exercises in the remainder of this module are based on the following two assumptions:

  • For practical purposes, the effect of the acceleration of gravity is the same regardless of the height of an object above the surface of the earth,provided that the distance above the surface of the earth is small relative to the radius of the earth.
  • In the absence of an atmosphere, all objects fall toward the earth with the same acceleration regardless of their masses.

Let's examine the validity of these two assumptions.

Newton's law of universal gravitation

This law states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. (Separately ithas been shown that large spherically symmetrical masses attract and are attracted as if all their mass were concentrated at their centers.)

Effect of gravity versus altitude

An object at the surface of the earth is approximately 3963 miles from the center of the earth. An object that is six miles above the surface of the earth(typical flying altitude for a passenger plane) is approximately 3969 miles from the center of the earth.

Therefore, (if I didn't make an arithmetic error) the gravitational attraction between the earth and that object changes by less than 0.5 percentwhen the object is transported from the surface of the earth to a position that is six miles above the surface of the earth.

For practical purposes, therefore, we can assume that the acceleration of gravity is constant up to at least 32000 feet above the surface of the earth.

Acceleration is independent of mass

Newton's law, as applied to the gravitational attraction of the earth, expressed in algebraic terms, looks something like the following :

f =E*m/d^2


  • f is the attractive force between the earth and another object
  • E is the mass of the earth
  • m is the mass of the other object
  • d is the distance between the center of mass of the earth and the center of mass of the other object

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
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.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Accessible physics concepts for blind students. OpenStax CNX. Oct 02, 2015 Download for free at https://legacy.cnx.org/content/col11294/1.36
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