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Section learning objectives

By the end of this section you will be able to:

  • Describe Newton's first law and friction a 1 m
  • Discuss the relationship between mass and inertia

The Learning Objectives in this section will help your students master the following TEKS:

  • (4) Science concepts. The student knows and applies the laws governing motion in a variety of situations. The student is expected to:
    • (D) : calculate the effect of forces on objects, including the law of inertia, the relationship between force and acceleration, and the nature of force pairs between objects
Section key terms
friction inertia law of inertia
mass Newton's first law of motion system

Before students begin this section, it is useful to review the concepts of force, external force, net external force, and addition of forces.

[BL] [OL] [AL] Ask students to speculate what happens to objects when they are set in motion. Do they remain in motion or stop after some time? Why?

Students may believe that objects that are in motion tend to slow down and stop. Explain the concept of friction. Talk about objects in outer space, where there is no atmosphere and no gravity. Ask students to describe the motion of such objects.

Newton's first law and friction

Newton's first law of motion    states that:

  1. A body at rest tends to stay at rest a 1 m
  2. A body in motion tends to remain in motion at constant velocity unless acted on by a net external force (recall that “constant velocity” means in a straight line and at constant speed). F n e t = 0 or ( F = 0 )

Newton's 1 st Law: F n e t = 0 Or ( F = 0 )

[BL] [OL] [AL] Discuss examples of Newton’s First Law seen in everyday life.
[BL] [OL] [AL] Talk about different pairs of surfaces and how each exhibits different levels of friction. Ask students to give examples of smooth and rough surfaces. Ask them where friction may be useful and where it may be undesirable.
[OL] [AL] Ask students to give different examples of systems where multiple forces occur. Draw free-body diagrams for these. Include the force of friction. Emphasize the direction of the force of friction.

At first glance, this law may seem to contradict your everyday experience. You have probably noticed that a moving object will usually slow down and stop unless some effort is made to keep it moving. The key to understanding why, for example, a sliding box slows down (seemingly on its own) is that a net external force acts on it to make it slow down. Without this net external force, the box would continue to slide at a constant velocity (as stated in Newton’s first law of motion). What force acts on the box to slow it down? It is called friction    . Friction is an external force that acts opposite to the direction of motion (see [link] ). Think of it as a resistance to motion that slows things down.


  1. Goes in the opposite direction
    Alt text
  2. Causes an object to slow down ( [link] )

Consider an air hockey table. When the air is turned off, the puck slides only a short distance before friction slows it to a stop. However, when the air is turned on, it lifts the puck slightly so that the puck experiences very little friction as it moves over the surface. With friction almost eliminated, the puck glides along with very little change in speed. On a frictionless surface, the puck would experience no net external force (ignoring air resistance, which is also a form of friction). Additionally, if we know enough about friction, we can accurately predict how quickly objects will slow down.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Practice Key Terms 6

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Source:  OpenStax, Updated tutor hs physics content - legacy. OpenStax CNX. Mar 16, 2015 Download for free at https://legacy.cnx.org/content/col11768/1.4
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