Lecture 4 Flashcards
name 4 types of energy
potential
kinetic
acoustic
thermal
what is the unit of energy
joules
1 joule of energy is required to raise 1 kg how far
10 cm
is there more energy in a photon or a joule
there is more energy in a joule
does a photon of visible light carry a lot of energy or just a little bit of energy
a very little bit of energy
what is the unit that we typically use when talking about photons
electron volt
a photon is a packet of what kind of energy
electromagnetic energy
what are the measurements of power
watts
energy that is used or expended in 1 sec is called
power
how much is 1 watt
1 joue of energy produced or used in 1 second
the human brain uses how many watts of power
about 20 watts of power
the human body uses about how many watts of power
100 watts
what is irradiance
intensity
what are the units for intensity of sound
decibels
what is the definition of a watt?
1 joule of energy produced or used in 1 second
what is the solar irradiance at the top of the earths atmosphere
1367 watts/meter 2
is the effect of solar flares big or small
small
what is the spectrum for visible light
400-750 nm
what are the units for intensity of solar energy
watts/m2
which is worse UVB or UVA
uvb
whcih is more harmlfull infrared or visible light
visible light
t/f UVB helps the skin make vitamin B
true
what does visible light promote
photosynthesis
which photon has more impact : visible light or uv
uv
what is the defintion of energy
ability to do work
what is the unit of energy
the joule
what is the calorie
a small unit of energy
what is the electron volt
a verrrrrry small unit of energy
what is the unit of power
watt
what is the definition of power
energy that is used or expended in 1 second
what is the defintion of intensity
amount of power reaching 1 square meter
what is solar irradiance
power from sun reaching 1 m2
which kind of uv radiation can break DNA strands
uvB
what does UVB use to convert into vitamin D in the skin
cholesterol
is the electron volt a big or small unit of energy
small
a photons ……can tell us about its energy in ev
wave length
what is the symbol for resistance
ohm
what is the unit for electric current
amp
what is the definition of an amp
coulomb/ second
what is the name for the unit of electric potential
volt
how much does 1 coulomb equal
6.24*10^18
what does volts times amps equal
power
how much energy is usally given through a defibrillator
100-200 joules
which has higher resistance , dry or wet hands
dry
