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HAPPYBIRTHDAY,

PRINCESS!

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ESSENTIAL QUESTION:

How can understanding variousphysical properties about motion beuseful in understanding everydayoccurrences?

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An Introduction to Dynamics

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COMPARISONo What is the acceleration of

the ball at the highest pointof its path?o Why would objects in motion

stop moving?o How fast is the object

moving?o How come the body move

to the left and not to theright?

o How high did the body rise?o Why did the object move to

the right?o What enabled the particle

to remain in the air? Why?o Why do objects at rest start

moving?o How long is the particle inthe air?

KINEMATICSo What is the acceleration of

the ball at the highest pointof its path?

o How fast is the objectmoving?

o How high did the body rise?o How long is the particle in

the air?

DYNAMICSo Why would objects in motion

stop moving?o How come the body move

to the left and not to theright?

o Why did the object move tothe right?

o What enabled the particleto remain in the air? Why?

o Why do objects at rest startmoving?

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FORCES

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What is a force? Give some of its

characteristics.o A push or a pull exerted by one body on another.

o A vector quantity

o May be called an interaction between two bodies.

o Can be classified either as

o a contact force

o non-contact force (also known as action-at-a-distance force).

agentreceiver

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FORCES

o Two basic forces in nature that explaininteraction between objects at themacroscopic level

1. Gravitational force

2. Electromagnetic force

Examples:o Elastic force in a spring

o friction

Rubber Band

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4 fundamental forcesFORCE RELATIVE

STRENGTHRANGE EXAMPLE

Strong nuclear force

10 39 10 − 5 withinthe nucleus

Weak nuclear force

10 34 10 − 5

Electricalforce

10 37 Neutral over large distancebut is effectiveover distancesof few meters

Gravitationalforce

1 Can act over any distance

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4 fundamental forcesFORCE RELATIVE

STRENGTHRANGE EXAMPLE

Strong nuclear force

10 39 10 − 5 withinthe nucleus

Binds nucleus

Weak nuclear force

10 34 10 − 5 Nuclear decay

Electricalforce

10 37 Neutral over large distancebut is effectiveover distancesof few meters

Contactforces liketension andfriction

Gravitationalforce

1 Can act over any distance

Universalinteractionbetween

bodies

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Scientists who studied about motion & forces

o Newton

o Maxwell

o Yukawa

o Glashow, Salam & Weinbergo Planck & Einstein

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ENRICHMENT ACTIVITIES(4TH E – ELABORATE)

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BY RLT: (pp. 120-125)

1. HANDS ON: Measuring Force (p. 122):Which activity required the greatestmagnitude of force? How do you know?

2. COOPERATIVE LEARNING: Muscular Forces(p. 122) . . . What does this activity tell usabout the nature of forces?

3. HANDS ON: Different Kinds of Forces (p.125):What forces are present in each of thetasks?

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HANDS ON: Measuring Force

Which activity required the greatestmagnitude of force? How do you know?

a. Open a cabinet door b. Pull a chair

c. Lift a bag

d. Break a matchstick e. Double the length of a rubber band

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COOPERATIVE LEARNING: Muscular Forces (p.122) . . . What does this activity tell us aboutthe nature of forces?

Forces havemagnitude and

direction. Itsmagnitude &

direction may vary.

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HANDS ON: Different Kinds of Forces (p.125)

a. Push a small can with its open end into apail of water.

b. Rub a plastic sheet with a silk cloth andplace the sheet near small bits of paper.

c. Get a magnet and place it near paper clips.

d. Stretch a rubber band by hanging weightson it.

Surface tension; Buoyant force

electrostatic force

magnetic force

elastic force & gravitational force