GRYMOEDD FORCES

Is gravity real -or does the Earth just suck?

A yw disgyrchiant yn bod – neu a yw’r Ddaear yn sugno?

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Sir Isaac Newton

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Pa ffrwyth ? Which fruit ?

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Newton?

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Grym yw disgyrchiant Gravity is a force

When gravity pulls something towards the Earth –- we call this force the weight.

Wrth i ddisgyrchiant dynnu rhywbeth tuag at y Ddaear -

- y pwysau yw’r enw a roddir ar y grym hwn.

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Mesurir grymoedd mewn

Newtonau

Forces are measured in

Newtons Pwysau afal = tua 1 Newton

Weight of an apple = about 1 Newton

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Dewch I chwarae gêm!

Let’s play a game !

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Codi pêl ping pong Lifting a ping pong ball

gwelltyn

straw

Sugno ! Suck !

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pêl ping pong yn disgynping pong ball falling

Mae’r saeth yn cynrychioli grym disgyrchiant

The arrow represents the force of gravity

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The ball does not fall when your sucking force = force of gravitysugno /

suck

disgyrchiant gravity

How have I shown this ?

Nid yw’r bêl yn disgyn os yw’r grym sugno = grym disgyrchiant

gwelltyn

straw

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Which diagram shows the sucking force equal to the force of gravity?

Pa ddeiagram sy’n dangos grym sugno sy’n gyfartal â grym disgyrchiant?

gwelltyn

straw

gwelltyn

straw

gwelltyn

straw

sugno / suck

sugno / sucksugno /

suck

disgyrchiant gravity disgyrchiant

gravity

disgyrchiant gravity

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The ball does not fall when your upward force = force of gravity

Nid yw’r bêl yn disgyn os yw y grym gwthio i fyny = grym disgyrchiant

disgyrchiant gravity

sugno / suck

gwelltyn

straw

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Disgyrchiant ochr arall Gravity down under

y byd Nid yw

pobl yn syrthio oddi ar y Ddaear

People do not fall off the Earth

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- dau wrthych sy’n cael eu gollwng ar yr un pryd

-two objects dropped at the same time

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Ar y Lleuad Apollo 15 On the Moon

http://nssdc.gsfc.nasa.gov/planetary/image/featherdrop_sound.mov

A heavy geological hammer and a falcon feather were dropped from the same height. They hit the lunar surface at the same time.

astronaut David Scott

NASA pictures

Cafodd morthwyl daearegol trwm a phluen hebog eu gollwng o’r un uchder. Gwnaeth y ddau daro wyneb y lleuad ar yr un pryd.

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Y LleuadThe Moon

Y DdaearThe Earth

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Y DdaearThe Earth

Y LleuadThe Moon

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Ar y Lleuad On the Moon

NASA pictures

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Esgidiau trymion iawn - Pam?Very heavy boots- Why?

Answers? No gravity on the Moon Weightless on the Moon To stop them floating

away They weigh very much

less than on Earth To stop huge bounces The Moon’s gravity is

very much less than the Earth’s gravity

Atebion?• Dim disgyrchiant ar y

Lleuad• Dibwysedd ar y Lleuad• Rhag ofn iddynt arnofio i

ffwrdd• Maen nhw’n pwyso llawer

llai nag y maen nhw ar y Ddaear

• I osgoi bownsiadau anferth• Mae disgyrchiant y Lleuad

yn llawer llai na disgyrchiant y Ddaear

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DISGYRCHIANT GRAVITY

Things fall

Things have weight

Things stay in place

Mae pethau’n syrthio

Mae gan bethau bwysau

Mae pethu’n aros yn eu lle

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Dim Disgyrchiant No Gravity

Would an apple fall? Would things stay

on earth? What would

happen?

What? Why? How?

A fyddai afal yn syrthio?

A fyddai pethau’n aros ar y ddaear?

Beth fyddai’n digwydd?

Pam? Beth? Sut?

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……keep asking questions

-like Newton!

…….aliwch ati i ofyn cwestiynau

-fel Newton !