P5

When are the forces of gravity only noticeable?

Why do planets stay in orbit around the sun?

What is the force applied to the centre of an orbit?

The larger the mass the greater/weaker the gravitational force?

The further away an object is the smaller/greater the gravitational force

Force is indirectly proportional to...

Why is the orbit time for a planet closer to the sun less?

How does a satellite orbit the earth?

Whereabouts do polar satellites orbit?

How long do polar satellites take to orbit the earth?

How much of the earth's can polar satellites see?

What are polar satellites used for?

Whereabouts do geostationary satellites orbit?

How long do geostationary satellites Take to orbit?

What are geostationary satellites used for?

How do you calculate the distance travelled by a satellite?

All geostationary satellites must be in different/the same orbit

Why can't geostationary satellites be too close together?

What is a scalar quantity?

What is a vector quantity?

What are vectors normally represented by?

What is 3m/s to the right + 2m/s to the left?

How is the resultant of two forces that are not in the same direction found?

What does U stand for in equations of motion?

What does V stand for in equations of motion?

What does A stand for in equations of motion?

What does S stand for in equations of motion?

What does T stand for in equations of motion?

What is the acceleration of an object thrown into the air?

What is the velocity of a ball at the top of its ascent?

A ball thrown horizontally from the top of a tower will fall at the same rate as a ball dropped from the top of a tower. True or false?

What is the trajectory of a ball thrown horizontally?

What equation do we use to work out the horizontal motion of a ball?

What type of horizontal velocity does a ball have (been thrown from tower)?

What is the resultant velocity?

What do forces always occur in?

The action and reaction pairs of forces are... (3 things)

What law is it that states that forces come in pairs?

Why do we have weight?

What is the opposite force to us being attracted to Earth?

Why does a gun recoil after a bullet is shot out of it?

What is the opposite of an explosion? What is still conserved?

How does pressure build up in a gas container?

How does a larger volume increase pressure?

How does increasing the temperature increase pressure?

Force = rate of change of (what?)

As a rocket moves up, the hot gases released move ......... . Momentum is ................ . This means that the high momentum of the large massed rocket moving up is ............... by the high velocity of the exhaust gases.

What are microwaves sent into space by?

What satellites are used to receive, amplify and re-transmit the microwaves back to earth?

When microwaves return to earth, what are they received by?

Why are digital signals used for satellite communication?

What frequencies of radio waves does the ionosphere reflect?

What happens when radio waves with frequencies above 30 MHz meet the ionosphere?

What range of frequencies are used for satellite communication?

How high above the earth do geostationary satellites orbit?

Why is the size of a geostationary satellite's dish many times bigger than the microwaves wavelength?

Why do the receiving dish and transmitting dish need exact alignment?

What do microwaves do as they are fired into space?

What is the ionosphere?

What do radio waves undergo as they enter space?

The smaller the size of a gap the greater/lesser the diffraction

Which of these diffracts more.... radio waves or TV signals?

When does maximum diffraction occur?

Why would radio waves diffract in a hilly area?

What will happen if you place two speakers (connected to the same output) and place them about 1 metre apart?

What does it mean when two crests/troughs overlap?

What does it mean when a trough and a crest overlap?

What is constructive interference?

What is destructive interference?

Show the diagram for constructive interference

Show the diagram for destructive interference

In terms of half wavelengths, when does constructive interference occur?

In terms of half wavelengths, when does destructive interference occur?

Generally, when does interference between light waves occur?

What kind of interference is light bands and what kind of interference is dark bands?

Why do the slits have to be closer together than the speakers?

What kind of waves are electromagnetic waves?

When is light polarised?

How do polaroid sunglasses work?

What did Newton think of light as and why was he wrong?

What did Huygens think of light as?

Why does refraction occur?

What does light do as it enters a more dense medium and why?

What does light do as it enters a less dense medium and why?

What is the refractive index?

What is the equation for working the refractive index?

Why does dispersion occur?

What does Snell's law state?

When light passes from a more dense medium into a less dense medium the angle of refraction is ................ than the angle of incidence

What is the critical angle?

What happens if the critical angle is exceeded?

What do optical fibres rely on?

What three things are optical fibres used for?

The higher the refractive index of a material, the higher/lower its critical angle

n = 1
----
?

A parallel beam of light from a distant object can be .................... to a focus in the ........... plane

What happens if the beam is parallel to the principal axis?

What will a diverging beam from a near object do?

How does a camera work?

How is a projector different to a camera?

What can we do to find the position and size of an image created by a convex lens?

What happens to the top ray?

What happens to lower ray?

What are the two properties of an image formed by a magnifying glass?

What is the difference between simple and more advanced cameras?

What is the aperture?

What do the condenser lenses do in a projector?

What does the curved mirror do in a projector?

Magnification =

Why can't the image produced by a magnifying glass be projected onto a screen?