Week 7 - Physical Science 2

Question 1

Non contact forces

Answer 1

Gravity or magnetism

Question 2

Electromagnetic spectrum

Answer 2

Range of light that exists

Blue - busy (faster)

Red - lazy (slower and bigger)

Question 3

Light and colour frequency

Answer 3

Light and colour frequencies are different and individual

Each colour has its own wave length

Question 4

Transmission of light

Answer 4

Light can travel through a vacuum

Transmitted light - let through

Reflected - turned after striking a surface

Absorbed - transformed into heat energy

Question 5

Absorption

Answer 5

If a light wave of a given frequency strikes a material with electrons having the same vibrational frequencies, those electrons will absorb the light wave and turn it into vibrational motion and thermal energy

Question 6

Reflection and transmission

Answer 6

Occur because the frequencies of light waves do not match the natural frequencies of vibration of the objects

Question 7

Transparent

Answer 7

Can see through it

Vibrations of electrons are passed onto neighboring atoms through the material and reemitted through the other side of the object - such frequencies are transmitted

Question 8

Opaque

Answer 8

Can’t see through it

The vibrations of the electrons are not passed from atom to atom of the material
The electrons of atoms on the materials surface vibrate for short periods of time and emit through a light wave

Question 9

Reflection

Answer 9

Light bounces off things

Reflection of light off surfaces

Rays go towards the eye - arrows represent the way the light travels

Question 10

Refraction

Answer 10

Light is made up of different colours

Depending on its wavelength when it moves through different materials

Question 11

Is white a colour?

Answer 11

Materials have frequencies

Colour comes from natural frequencies

White is a combination of colours

Primary colours for mixing light are red blue and green

Question 12

The 7 colours on the spectrum- how to remember them

Answer 12

Red
Orange
Yellow
Green
Blue
Indigo
Violet

Richard York Gave Battle In Vein

Question 13

Does light or sound travel faster?

Answer 13

Light travels faster than sound

Question 14

What are shadows

Answer 14

Shadows occur when a path of light is blocked by the object

Shadow is formed on the opposite side of the object to the light source

Closer the object - the larger the shadow

Shadows never vanish

Question 15

3 parts of a battery

Answer 15

Cathode (+)

Electrolyte (conducts electricity when dissolved in water)

Anode (-)

Question 16

How does a battery work

Answer 16

Chemical reaction causes a build up of electrons at the anode

The charges repel

When the circit is closed (a wire connects the cathode and anode) the electrons will be able to get to the cathode by going through the wire

Question 17

Wires

Answer 17

Electrons will leave valence shell because metal is a better conductor

Circuit - all electrons move in same direction

Question 18

Battery

Answer 18

Contains chemicals which have chemical energy. When the chemicals react with each other they generate electrical energy. The battery is a source of electrical energy and provides the push to make the electrons move

The electrons carry the electrical energy from the battery to the bulb - energy transfer

The bulb changes electrical energy into light and heat energy - transformation

Question 19

Push

Answer 19

Voltage

Question 20

Energy transfer

Answer 20

‘Conga line’ analogy

Question 21

Transformation

Answer 21

Electrical energy to light and heat energy

Question 22

Electrical conductors and insulators

Answer 22

Materials contain free electrons that can move around (conductors)

Conductors allow the passage of electrical current

Conductor is an atom that does not hold onto its valence electrons well

Insulators do not want to join

Question 23

Conga line analogy

Answer 23

Valance electrons will not move from atoms

Question 24

Solar energy

Answer 24

Both light and heat energy

Heat energy from the sun transferred to electricity (solar panels)

Question 25

Wind energy

Answer 25

When the sun heats up the atmosphere - air moves and it creates wind

Wind turbines

Question 26

Water energy

Answer 26

Hydroelectricity

Tidal energy

Wave energy

Question 27

Geothermal energy

Answer 27

Energy from earths crust

Question 28

Balanced forces

Answer 28

Balanced forces do not change motion - they have the same effect as if there were no forces involved

When forces are balanced - the motion of object is unaffected

Unbalanced forces change the motion of objects

Question 29

What is gravity

Answer 29

Gravity is a non contact force

Force of attraction

Force of attraction depends on the objects mass or how close the objects are to each other

Question 30

Mass

Answer 30

Mass is the same on earth or moon

Question 31

Weight

Answer 31

Depends on gravitational force and varies throughout the universe

Question 32

Gravity and space

Answer 32

Gravitational force depends on the mass of the planet

Larger the mass of the planet the greater the gravitational force will be

Question 33

Inertia

Answer 33

The resistance of any physical object to change in its state of motion, including changes to speed or direction