Physics Test

Question 1

•wave •wavelength •crest •trough •amplitude •wave depth •frequency

Answer 1

Wave: transferring energy from one point another without transferring matter Wavelength: distance from one point to other same place •crest: highest point on wave •trough: lowest point •amplitude: wave height from rest position to crest •wave depth: rest position to trough •frequency: rate of wave repeating

Question 2

Electromagnetic radiation Electromagnetic spectrum -radio waves -microwaves infrared waves -ultraviolet rays -x rays -gamma rays

Answer 2

•radiation: energy that can travel •spectrum: range of wavelength from radio to gamma rays -radio waves: longest wave bcuz lowest frequency used for MRI -microwaves: shorter wave lengths than radio waves -infrared waves: shorter wavelength than microwave (are heat in hot tea) -ultraviolet: shorter wavelength and higher frequency than visible light(Disinfect water) -X-rays: very high radiation -gamma rays: high radiation to kill cancer cells

Question 3

What is the sped of light Critical angle

Answer 3

•speed of light 3.00x10^8 m/s •criticism angle: 48.8

Question 4

•translucent •transparent •opaque

Answer 4

•translucent: transmit some light not enough to see through Ex: shower door •transparent materials absorb & reflect very little light transmit light freely you can see right through •Opaque:absorb and reflect light but they do not transmit

Question 5

Cornea Pupil Iris Retina Convex lens Photoreceptors Rod cells Cone cells Blind spot Astigmatism Aqueous humor Vitreous humor Sclera Optic nerve

Answer 5

•cornea: outer surface directs light into eye •pupil: dark circle hole allowing light made of muscle called iris •iris: muscle control size of pupil •retina: back of the eye acting like a projection screen for light •eye is a convex lens able to adjust focal length •photoreceptors: cells in retina absorbing light •rod cells: detects shape and movement •cone cells: detect primary colours green red blue •blind spot: no photoreceptors can’t detect light but brain fills with colours •astigmatism: eye can’t create clear image bcuz of irregular shape of cornea -one type is seeing unclear horizontal line -2nd type is seeing unclear vertical lines •aqueous humor: fluid between lens and cornea •vitreous humor: jelly like filled behind the lens •sclera: white outer layer in front w/cornea •optic nerve: transmit to brain from retina

Question 6

Shadows Umbra Penumbra

Answer 6

Occurs when opaque object blocks light from the light source •light Source large compare to object blocking light=shadows will not have sharp edge cuz object blocks only part of light •wider the light Source: the more blurred the shadows will be •umbra: part of shadow where all light rays are blocked •penumbra: non point light forms partial shadow (the light source is not a point, bigger light)

Question 7

Diffuse reflection Regular reflection

Answer 7

•diffuse: light rays reflecting off uneven surface not parallel but scattered in different directions •regular: light rays hit smooth surface staying parallel

Question 8

Normal Law of reflection

Answer 8

Dash line perpendicular to mirror •angle of incidence equals angle or reflection

Question 9

Calculate magnification

Answer 9

M=hi/ho M= -di/do

Question 10

Index of refraction Snells law

Answer 10

•n=c/v N=index of refraction of material C=speed of light in vacuum V=speed of light in medium •snells law: use to calculate new angle

Question 11

Refraction Total internal reflection critical angle

Answer 11

•Ray travelling to low refractive index to higher=bending toward normal Light travelling from denser to less=bend away •total: light reflects inside a wall in denser medium •critical angle: 48.8 degres refracted Ray does not leave, light is trapped inside dense material

Question 12

Mirage Dispersion

Answer 12

Mirage: an image of distant object produced when light refracts through air to different densities like pavement •dispersion: is the refraction of white light separating wavelengths or colours

Question 13

Ray model of light

Answer 13

Explain why the brightness of a light changes with distance

Question 14

1.Incandescence 2.Fluorescent 3.Phosphorescence 4.Chemiluminescence 5.Electric discharge 6.LED 7.Plasma 8.Liquid crystal

Answer 14

1. Thin wire (filament) turns on to heat, inefficient 2. Light bulb filled with mercury vapour and coated with phosphor 3. Stores energy ex: glow in the dark 4. Light produce w/ chemical reaction w/o rise in temp. Ex: glow sticks 5. Electric current passing ex: Vegas signs 6. Electrical energy into light energy ex: phones 7. Tiny fluorescent lights to neon gas produce colour ex: tv 8. White light(fluorescent) shining behind liquid crystal ex: computer