Physics test 3 grade 10 Flashcards
G (giga)
billion or 10^9
M (mega)
Million 10^6
k (kilo)
thousand 10^3
d (deci)
tenth 10^-1
c (centi)
hundredth 10^-2
M (milli)
thousandth 10^-3
µ (micro)
millionth 10^-6
n (nano)
billionth 10^-6
scientific notation
number x 10^ something
add as many zeros as the exponent to the right of the number
if exponent is negative, add zeros to the left of the number
Transverse waves and example
(4)
carry energy
is the result of an up and down motion
oscillations (movements) are at a right angle to the direction of travel
example would be light waves
Longitudinal waves (4)
to and fro movements are in the same direction as the direction of travel
section where waves are bunched up are compressions
section where waves are stretched out is called rarefaction
example includes sound waves
speed of waves is measured in
m/s
frequency is measured in
hertz or (Hz)
the time for one oscillation is called ____ and is measured by
the period, 1 / frequency
wavelength
the distance between any point on a wave and the equivalent point on the next
measured in meters λ
amplitude
the max distance a point moves from its rest position when a wave passes
wave equation
speed = frequency x wavelength
V = f x 𝞴
m/s = Hz x m
triangle = v
λ x f
crest/peak
the top part of the wave
trough
the bottom part of wave
when two waves travel towards each other one on top and one on the bottom what happens when they meet
they create a straight line
when two waves travel towards each other on the same side what happens when they meet
the width doesnt change, but the amplitude doubles
time period and frequency
time period = 1/frequency
frequency = 1/time period
speed of sound
343 m/s
speed of light
300 000 000 m/s
when are electromagnetic waves emitted
when charged particles oscillate or lose energy in some way
relationship between energy, frequency, and wavelength
higher the frequency, greater the energy, shorter the wavelength
With reference to the electromagnetic spectrum and human actions explain why some people might say that ‘mobile phones cook your brain’
Some people might say that mobile phones ‘cook your brain’, because of the technology they have inside them. Since the technology has the same heating effect as microwave ovens for example, people are concerned that the microwaves that phones emit will heat up (or cook) our organs. Since phones are used for phone calls and are generally held near our head, some people’s concern is that they will damage our brain.
features of electromagnetic waves (4)
travel through vacuum
all have a speed of 300 000 000 m/s
all transverse waves
all transfer energy (lose energy when radiates these waves, gains energy when absorbs these waves_
Radio waves (4)
average wavelength of 10 m
can be as long as a football pitch
longest wavelength and least amount of energy
used for long distance radio, local radio, tv, phones, satellites, wifi, mocrowave ovens
Infrared (2)
average wavelength of 10^-4
radiant heaters and grills, tv remote controllers, security alarms, lamps,
visible light (3)
10^-6 ish
only type of radiation visible to the eye
sunlight
ultraviolet (2)
10^-8
causes tanning, skin cancer, eye damage, kills bacteria, and causes fluorescence
x rays (2)
around 10^-10
used for x rays, photography, causes cancer but can also kill cancer cells
gamma rays (5)
around 10^-13
emitted by radioactive materials
uses and effects as for x rays
used for sterilizing medical quipment and food
shortest wavelength and most energy
order of electromagnetic spectrum from longest wavelength/least energy to shortest wavelength/highest energy
radio waves, infrared, visible light, ultraviolet, x rays, gamma rays
mechanical waves
disturbance in matter that transfers energy through the matter
requires a medium to pass through
looses energy as it travels
what do electromagnetic waves consist of
vibrating electric and megnetic fields
Up to what temperature are infrared waves produced (and not visible light)?
At around 700 degrees C , infrared becomes visible light
What detector and emitter of these waves might you be carrying?
Microwaves are used in mobile phones
How does the x-ray behave when it encounters different parts of the body?
Long wavelength X - rays can penetrate through flesh, but not bone, allowing us to get imaging of the bones. The dark areas are flesh and white areas are bone.
All X - rays are dangerous as they harm living cells in our bodies, causing mutations or cancer. Interestingly, concentrated beams of X - rays can be used to treat cancer as well. In terms of reduction, doctors wear lead vests, and depending on the injury, some patients will too.
Types of mechanical waves
transverse, longitudinal, and surface waves (combination)
how will electromagnetic waves interact with matter
reflect, refract, or diffract
