Science Flashcards

Task 4

What are waves?

they transfer energy from one place to another, without the transfer of matter

What are the two types of waves?

Transverse and Compressional

What are the features of a transverse wave?

Crest, trough, amplitude, wavelength,

What are the features of a compressional wave?

Compression and rarefaction

What does a high and low frequency result in?

High frequency = short wavelength

Low frequency = long wavelength

What is the wave equation?

Velocity = frequency x wavelength

What type of wave is sound?

A compressional wave

What does larger and smaller amplitude result in?

Larger amplitude = Louder sound

Smaller amplitude = Softer sound

What does a higher and lower pitch result in?

Higher pitch = Higher frequency

Lower pitch = Lower frequency

What medium does sound travels the fastest in?

Solid, then liquid and gas

What is the law of reflection?

The angle of reflection is always equal to the angle of incidence

Where does a concave mirror bring light to a focus at? Give an example.

The light converges and brings light to a focus in front of the mirror e.g makeup mirror

Where does a convex mirror bring light to a focus at? Give an example.

The light diverges and brings light to a focus behind the mirror e.g intersection mirrors

What are the 3 different types of surfaces?

Opaque, transparent, translucent

What is refraction?

When light enters and leaves a different medium on an angle and is bent as a result

What happens to light when it enters a more dense medium?

It refracts towards the normal

What happens to light when it enters a less dense medium?

It refracts away from the normal

What happens to light rays when it enters a concave lens?

The rays diverge

What happens to light rays when it enters a convex lens?

The rays converge

What is the order in which light enters the eye?

Cornea, aqueous humor and pupil, lens, virtuous humor and retina, optic nerve

What are the 2 photoreceptors?

Cones and rods

What are the 3 different cones and their colours?

L cones - red

M cones - green

S cones - blue

What are cones responsible for?

Colour vision

What are rods responsible for?

Brightness

Where are photoreceptors located?

In the retina

List the electromagnetic spectrum from least to most powerful.

Radio waves
Microwaves
Infrared Radiation

Visible Light

Ultra-Violet

X rays

Gamma rays

What is static electricity?

When an unbalanced charge on the surface of a substance causes electrons to move from one object to another because of friction

What is current?

The rate of the flow of electrons

What is current measured in and its symbol?

Amps, I

What is voltage?

The push of electrical energy carried by the current

What is resistance?

when there is a restriction in the current

What is voltage measured in and its symbol?

Volts, V

What is resistance measured in and its symbol?

Ohms, R

What are the 2 types of circuits?

Parallel and series

In a series circuit, how is current distributed?

It’s equal at all points

In a series circuit, how is voltage distributed?

It’s split up

In a parallel circuit, how is current distributed?

It’s split up

In a parallel circuit, how is voltage distributed?

It is equal at all points

State Ohms Law

Voltage = Current x Resistance
V = I x R

How do you calculate energy efficiency?

Energy efficiency = useful energy output/total energy input x 100

What are Earth’s 4 systems?

Biosphere, hydrosphere, lithosphere, atmosphere

What are the 2 parts of the mantle?

Asthenosphere and lithosphere

What are the main layers of the Earth?

Inner core, outer core, mantle, crust

Who created the theory of continental drift?

Alfred Wegner

What is the evidence of continental drift?

Jigsaw fit, rocks and mountains matching, fossils matching, climate data

What are convection currents and their purpose?

they are the driving force behind tectonic plates that are caused by cycling heat

What is a boundary?

Where 2 plates meet

What is a divergent boundary?

When two plates move away from each other causing magma to spew up

What is a convergent boundary?

When two plates come together and collide

What is a transform boundary?

when two plates slide past each other and eventually jolt passed each other releasing pressure

What is some evidence for plate tectonics?

older rocks get pushed aside for the new rocks being formed, different direction of the magnetism, chains of activity mark the boundaries, GPS coordinates change

What are folds?

When rocks bend without breaking as two plates collide 

What is oregoney?

formation of fold mountains when two plates collide

What is a fault?

when rocks crack under the pressure

What is a normal fault?

the plates diverge and cause the foot wall to sink

What is a reverse fault?

when the plates converge and the hanging wall rises

What is a strike slip fault?

when the plates transform sideways causing a mismatched landscape

How do mountains form?

when two plates converge and neither plates sink under the other

How do earthquakes form?

when enormous strain builds up in the plates and causes the plates to snap into a new position

What is the focus of an earthquake?

the point in the Earth’s crust where rock fracture generates an earthquake 

What is the epicentre?

the point directly above the focus

What scale is used to measure earthquakes? What does each scale represent?

Richter scale. Represents a 30 time increase in energy released

What are the 3 different earthquake waves?

P, S and L waves

What are P waves?

primary waves which are compressional waves and are the fastest

What are S waves?

secondary waves which are transverse waves and the 2nd waves to be detected

Which earthquake waves are body waves?

P and S waves

What are L waves?

Love waves which are surface waves that arrive last on the surface of Earth and are more destructive

How are waves detected?

using a seismometer 

How do you find the epicentre of an earthquake?

by comparing the time interval between P and S waves at different locations

What is triangulation?

using readings from three different seismic stations to find the epicentre

How do tsunamis form?

when earthquakes occur underwater causing series of waves that travel across the ocean

What happens when waves enter shallow waters?

they slow down and the waves further back start to catch up causing the waves to bunch up