11.1 What is light

radiation

method of energy transfer that doesnt need medium; energy travels at the speed of light

Electromagnetic Wave

a wave has both electric + magentic parts, and does not need a medium

visible light

EM waves that human eyes can detect

EM spectrum

classification of EM waves from low to high energy

medium

physical substance through which energy can be transferred

what does transfer of heat require

a transmission medium

does light need a medium

no, because it travels through the vacuum of outer space

example of radio waves

radio, tv signals, radar, phones

example of microwaves

microwaves, GPS

example of infrared

remotes, keeping food warm, heat detection

examples of UV light

sunburns, “black” light, also increases risk of skin cancer

examples of X-Rays

cancer treatment, medical imaging, takes photos of galaxies

examples of gamma rays

cancer treatment

visible spectrum

continuous sequence of colours that make up white light

how fast can light travel in 1 sec

light can travel 7.5 times around the earth