Newtons Laws With Good Pictures

8/13/2019 Newtons Laws With Good Pictures

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Have you ever stopped to look at a

car accident?


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When you look at a car accident you arelooking at the results

of the Forces of Motion around us.

Newtons Laws of Motion


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First we need to define the

word FORCE:

The cause of motion (what

causes objects to move) Two types of forces

Pushes

Pulls

REVIEW


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Forces are measured in

Newtons SI unit of force

Symbol: N

Measured by using a spring scale

REVIEW


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Forces may be balancedorunbalanced Balanced forcesall forces acting

on an object are equal There is NO MOTION

Unbalanced forcesone or more

forces acting on an object arestronger than others

There is MOTION

A NET FORCE

REVIEW


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Newtons Laws

First LawInertia

Second LawAcceleration,

Force & Mass

Third LawAction-Reaction


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Law # 1:

Every object at rest remains at rest and

every object in motion continuesmoving in a straight line at a steady

rate unless a force acts it on.

This is the principle of inertia.

Can you tell me how this principle

applies to car accidents?


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First Law

Inertia & Mass

Massis the amount of matter in an

object.

The more MASSan object has, themore INERTIAthe object has.

Bigger objects are harder to start &

stop.

http://toons.artie.com
http://toons.artie.com/http://toons.artie.com/


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Law # 2

The amount of force needed to change

the speed of an object depends on themass of the object and the amount of

acceleration (or deceleration) needed.

This is the principle of acceleratedmotion.

Can you tell me how this law applies tocar accidents?


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Second Law

Acceleration & Force

The more forceplaced on an object, the

more it willaccelerate [change its motion].

Acceleration & Mass

The more mass[or inertia] an object has, the

more forceit takes to accelerate the object.


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Second Law

Force = Mass x Acceleration

Example: A 25 g object with an accelerationof 4 m/s2will have a force of ______

Newtons.


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Law # 3

For every action there is an equal and

opposite reaction. When an object is pushed

or pulled by a force in one direction, another

force pushes or pulls on it with equal strength

from the opposite direction.Forces come in pairs, called action-reaction

pairs.

How does this law apply to car accidents?


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Third Law

ActionReaction

Forces are always produced in pairs with

oppositedirections & equalstrengths.

For every force there is an equaland

oppositeforce.


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Third Law

ActionReaction

ActionReaction Forces act on different

objects

When you kick a soccer ball, you exert a force onthe ball and the ball exerts a force on you. The

harder you kick the bigger the force on you (kicking

REALLY hard might hurt.)


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Third Law


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A swimmer pushes water back with

her arms, but her body moves

forward.

Which Law?


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A frog leaping upward off his lily pad ispulled downward by gravity and lands

on another lily pad instead of continuing

on in a straight line.

Which Law?


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After you start up your motorcycle, as

you give it more gas, it goes faster.

Which Law?


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Which Law?

A pitched baseball goes faster than one that

is gently thrown.


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Which Law?

When you paddle a canoe, the canoe

goes forward.


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Which Law?

As an ice skater pushes harder with his

leg muscles, he begins to move faster.


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Which Law?

A little girl who has been pulling a sledbehind her in the snow is crying because

When she stopped to tie her hat on, the

sled kept moving and hit her in the backof her legs.


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All about Forces!

A. B.

C.

D.
http://www.engineeringinteract.org/resources/parkworldplot/flash/concepts/allaboutforces.htmhttp://www.bbc.co.uk/schools/scienceclips/ages/10_11/forces_action.shtmlhttp://www.engineeringinteract.org/resources/parkworldplot/flash/concepts/allaboutforces.htmhttp://www.bbc.co.uk/schools/scienceclips/ages/10_11/forces_action.shtmlhttp://www.colorado.edu/physics/phet/simulations/projectilemotion/projectile.swfhttp://www.funderstanding.com/k12/coaster/

Newtons Laws With Good Pictures

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