Unit Four Exam Flashcards
What is work and it’s units
Energy used to move a distance, measured in joules
What is the formula for work
Force X distance
What things will affect the amount of work done
Force and distance
What is power and it’s units
Rate at which work is done, how fast
Measured in watts
What is the formulas for power
Force X d/ t
W/t
What are the different forms of energy
Kinetic and potential
What are examples of kinetic and potential energy
Kinetic: Heat, light, sound, mechanical
Potential: chemical, nuclear
What is the law of conservation of energy
Energy can’t be created or destroyed only converted into one form or another
What type of energy transformation is a boy eating an apple then walking to work
Chemical to mechanical
What type of energy transformation is gasoline in your car used to drive
Chemical to mechanical
What type of energy transformation is turning on a light
Electric to light
What type of energy transformation is hair dryer being turned on
Electric to heat
If two people collide how does the amount of energy before the collision compare to after and what law is this
It is the same and it is the law of conservation of energy
Why is the amount of potential energy at the top of a roller coaster I’ll is not the same as kinetic energy at the bottom of the hill
The energy at the bottom is slightly less because some was converted to hear by friction
What is kinetic energy, and units
Energy of motion and it is measured in joules
Formula for kinetic energy
KE= 1/2m v(2)
What is potential energy, what is it measured in
Stored energy. Joules
What is the formula for potential energy
P= w * h P= h X m X g
What is a medium and give three examples
The material that gets disturbed, through which a wave travels
Air, water, steel
Electromagnetic waves are fastest in what medium
Vacuum, no medium
What type of wave is a sound wave
Longitudinal
What type of wave is a light wave
Electromagnetic transversal
What type of waves are electromagnetic waves
Transverse waves, disrupt the electrical and magnetic field, radio, heat waves, visible, uv, X-Ray, gamma
What is the formula for wave speed,
V= f X wl
What is the formula for wavelength
Wl= v/f
What is the formula for frequency
F = v/wl
What are the units for frequency, wavelength, and wave speed
Frequency= hz
Wavelength= m
Wave speed= m/s
What is it called when a wave bends as it goes from one medium to another
Refraction
List the energies of the electromagnetic spectrum in order from longest to shortest wavelength
Radio, tv, micro, infared, visible, ultraviolet, X-Ray, gamma
What is period
Period is how fast it takes for one wave to pass in seconds
What is frequency
Frequency is how many waves pass per second
What is the formula for frequency
1/p
What is the formula for period
1/f
What type of wave travels fastest in solids
Longitudinal
In music the term pitch is what
Frequency
What types of EM radiation are used to fight cancer
Gamma
What are ultrasounds used for and what type of waves do they use
Ultrasonic and to see babies and internal organs
What type of wave is harmful to our skin but also beneficial in small amounts
Ultraviolet, can cause burns or skin cancer but also gives us vitamin d
What is the Doppler effect
Change in frequency due to motion
Will sound intensity increase or decrease as you move closer to the noise
Increase
What is an echo
Reflection of sound wave odd a smooth surface
What is reflection
Waves bouncing off flat, smooth surface
Why do we hear thunder after the lightning flash
Sound is slower than light
Why is the sky blue
Small molecules scatter blue and violet light around up in the atmosphere. We don’t see violet very well so it looks blue
Why are sunsets red
At sunset light travels through so much atmosphere to reach your eye that by the time it gets there all the blue has been scattered and only longer wave lengths get through.
What is current
Flow, more current= faster electrons
What is voltage
Electrical pressure ( how much energy each electron has) created by difference in electron pressure
What is resistance and give an example of a resistor
Opposition to the flow of electrons, an example is an insulator, wore thin or long
What is static electricity
Non flowing electrons
What is electric current
Flow of electron
What is coloumbs law
The force between the charges particles is directly proportional to amount of charge and inversely proportional to distance squared
What is coloumbs law formula
D(2)
What does coloumbs law say about distance and strength of attractions between chargers
If the amount of charge on two particles doubled then force between them is twice as much, if the distance between two particles is doubled the force between them is 1/4 of what it was before
What happens to the strength of attraction between two charged particles if the distance is doubled
The force between them is 1/4 of what it was before
What if distance is cut in half
Then the force is four times as much
What if the strength of one charge doubles
Then the force is doubled
What if strength of both charges doubles
The force between them is quadrupled
What is a series
When it’s one loop, only one path, If light is taken out then it doesn’t work
What is a parallel
More than one path, If a light is taken out the others still light
What is energy
The ability to do work
