physics topic 4

what type of wave is visible light

transverse wave

angle of incidence =

angle of reflection

angle of reflection=

angle of incidence

what is the normal line

a line perpendicular/at a right angle to the surface at the point of incidence

what happens to light when it is in more dense material

it slows down

when in more dense medium how does light act towards normal line

bends towards normal line

when in less dense medium how does light act towards normal line

bends away from normal line

label from a-d

a reflected ray

b incident ray

c angle of incidence

d angle of reflection

e normal line

Refraction practical

• draw around the block

• draw a normal line 90* from the top of the box

• aim the light towards normal line

• plot the angles/light rays

• turn of ray box + remove block

• connect the angles

• create another normal line for exiting angle

• measure and compare angles

What is the law of reflection

Angle of incidence = angle of reflection

What is a converging lense

• A lens that brings parallel rays of light together at a focus.

What is a diverging lense

A lens that spreads parallel rays of light apart as if they come from a focus.

What type of lens is this

Converging lens

what type of lens is this

Diverging lens

focal point on the right

Real

Focal point on the left

Virtual

3 lens facts

• lens is used to refract light in different ways

• transparent material that refracts light to improve the resolution of image

Higher the power of the lens the more it bends light

What type of wave is light

transverse wave

How fast does light travel 

3×10⁸ m/s

Properties of electromagnetic spectrum

• transverse waves

• can travel through a vacuum

• travel at the same speed in a vacuum

• transfer energy from one place to another

Order of electromagnetic spectrum

Radio, microwave, infrared, visible light, ultraviolet rays, x-ray, gamma ray

The lower on the electromagnetic spectrum means

Long wave length, low frequency

The higher on the electromagnetic spectrum

short wavelength, high frequency

Conduction

• The transfer of heat through a solid by particles (vibrating and passing energy to neighbouring particles.)

Convection 

The transfer of heat in liquids or gases (when warmer, less dense fluid rises and cooler, denser fluid sinks.)

Radiation

• The transfer of heat by infrared waves, (which can travel through a vacuum (no particles needed).)

Absorbtion

taking in energy

Emmiting

letting energy out to the surroundings 

Reflecting

energy makes contact with surface and changes direction

In transverse waves, oscillationss are

right angles to the direction of the wave

In longitudinal waves, oscillations are

parrallel to the direction of the wave

Frequency is

The number of waves passing a point every second

Period is

The length of time it takes for one wave to pass through a point

Calculation for wave speed

wave speed = frequency x wavelength

Units for wave speed

M/s

Units for frequency

Hz

Units for wavelength

M

frequencies with less that 20hz are

Infrasound

secondary waves are

longitudinal

Transverse

Slow

Can only pass through solids

Primary waves are

longitudinal

Faster

Can travel through solids and liquids

Wave period equation

1/frequency

Ultra sound is

Above 20,000 hz

Infrasound is 

Below 20,000 Hz

Equation for ocean thing

speed = distance/time

Transverse waves movements are

side to side 

Longitudinal waves movements ate

back wards and forwards as it compresses and releases

Seismic waves are

• Waves of energy that travel through the Earth after an earthquake or explosion.

Specular reflections are

• When light is reflected evenly from a smooth surface, producing a clear image.

diffuse reflection

• When light is scattered in many directions from a rough surface, so no clear image is formed.

Cm to metres is

/ by 100