# 1.2 Newton's first law of motion: inertia

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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 $a\propto \frac{1}{m}$
• Discuss the relationship between mass and inertia

• (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
 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 $a\propto \frac{1}{m}$
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). ${F}_{net}=0$ or ( $\sum F=0$ )

## Newton's 1 st Law: ${F}_{net}=0$ Or ( $\sum F=0$ )

[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.

Friction:

1. Goes in the opposite direction
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.

where we get a research paper on Nano chemistry....?
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
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
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
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