1-7 Forces in the universe

• Natuurkunde
• Middelbare school
• vwo
• Leerjaar 3

Forces in the universe 

(p. 20)

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Stationary

- Writingbook

- Pen, pencil

- Calculator

- iPad

Mark

- NO

Lessonup

- YES

Schoolbags in

the cupboard

Phones in teh phone bag

Lesson goals:

• Explain why the planets move around the sun.
  
• Explan the difference between gravity and weight.
• Explain what weightlessness is.

Everything in the universe experiences gravitational force...

...not only the things on earth.

The moon also experiences

a gravitational force due to

the earth.

Why does a planet not move away from the sun?

Because a planet is

attracted to the sun.

Why does a planet not collide with the sun?

Because a planet moves with a 

high speed past the sun.

With each turning motion of a planet

there is a  centripetal force.

Elliptical orbits

Almost circular.

The difference between gravity and weight...

Gravity works on an object

itself and weight works on

the support, 

e.g. the surface, rope

or handles of a crate when

lifting.

Weight

Weight is calculated with the the

equation

On earth it is g = 9,8 m/s² but on other planet or on a star it is probably different.

G=F​z​​=m⋅g

Mass

The amount of substance that something is made up of.

Weightlessness

If you jump out of an aeroplane your

body is in free fall. 

Because your body is not supported

anywhere you feel weightless.

What do we call the shape of the orbit a planet has around the sun.

Why does a planet not move away from the sun?

1. Gravity
2. Weight
3. Velocity
4. Support

Why does a planet not fall toward the sun?

1. Gravity
2. Weight
3. Velocity
4. Support

What is the difference between gravity and weight?

Now do the following

26 up to 29 

Answer digitally.