# Chapter 2-2 Notes newton laws by ajizai

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In Friday’s gizmo over weight and mass which
planet had the most gravity, why is this?
Focus
 With your partner, think of an example of an
object in your daily life that keeps on moving
forever without anything pushing it along.
Chapter 2-2 Notes

Newton’s Laws of Motion
Newton’s first law states that:
An object at rest remains at rest,
and an object in motion remains in
motion at constant speed and in a
straight line unless acted on by an
unbalanced force.
Briefly explain what this    Once something
means.
is moving then it
will keep moving
forever without
anything pushing
it along, until
something else
pushes or pulls it.
At rest example:
1) A golf ball balanced on
a tee
2) A ball on the floor

In motion example:

1) A bowling ball rolling
2) A person in a moving
car that stops
But objects don’t stay in    True. Friction does not
motion forever …….          allow objects to stay in
motion forever. But,
friction is an example of
Unbalanced
an ________________
__________________
Force
so Newton’s 1st law still
applies.
 Inertia is
the tendency of all
objects to resist any
change in motion.

Example – when a car
causes you to go
forward.
How does mass impact    Small mass = less
inertia?              inertia
Large mass = more
inertia

- ex:
Trying to throw a
marble or trying to
throw a bowling ball
 Newton’s second law of
motion states: The
acceleration of an object
depends on the mass of the
object and the amount of force
applied.
In other words ……..    Acceleration depends
on how heavy an object
is and hard you push.

Acceleration depends
on mass and force.
State the equation used.    F=ma when F is equal
to force or weight, m is
Draw the circle from the     equal to mass and a is
chalkboard here.           equal to acceleration.
This solves for force.
 A=F/m this solves for
remember the formulas.
 M = F/a this solves for
mass
Practice problems:
Remember!! Write the equation, plug it in, and
solve.

Freddie is skiing. What’s his force if his mass is
20kg and is accelerating at a rate of 5 m/s²?

F=mxa

20 kg x 5 m/s² =

100 N
2) Jon is pushing a 350 kg crate with a force of
5N. What is the acceleration?

A=F÷m

5 N ÷ 350 kg =

0.014 m/s²
3) Jenny dropped a bowling ball that falls to the
ground with a force of 12 Newtons. The
acceleration of the bowling ball is 9.8 m/s²
due to gravity. What is the mass?
m=F÷a

12 N ÷ 9.8 m/s² =

1.224 kg
Focus
 Write 2 original (don’t use the car example
from the notes) examples of inertia.
 Newton’s third law
states:
Whenever one object
exerts a force on a
second object, the
second object exerts an
equal and opposite
force on the first.
Or briefly stated as …..   All forces act in pairs. If a
force is exerted another
force occurs that is
equal in size and
opposite in direction.
Action  Reaction    Some examples are:
Swimmer –
action force = hand
hitting water
reaction force = water
moving
Can you always see the    No – this occurs in
action/reaction?         nonmoving objects also

Example = you sitting in a
chair

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