Science Midterm 2023 Flashcards
Mechanical wave?
A disturbance in matter the carrie energy from one place to another
Transverse wave?
Waves that move the medium at right angles to the direction in which waves are traveling
Ex. light low waves, low frequency
Longitudinal waves?
A wave going in the same direction as the medium
Waves?
A disturbance which results in a transfer of energy from one place to another
Wavelength?
Crest to crest
Period?
Time for one complete wave cycle to pass a point
Frequency?
Number of cycles that pass in a second
Radiation?
Physics, the process on which energy is emitted as particles or waves
Refraction?
The change in direction of a wave when it travels from one material to another
Law of Refraction?
Fast to slow- bends toward the normal low density to high density
Law of Reflection?
The same measure on both sides from the normal
Density?
Mass\volume
Mass?
How much matter is in an object
Volume?
How much space something takes up
Luminosity?
The amount of energy given off by a star
Nuclear fusion?
When two or more hydrogen join to make helium, this powers the star and will continue as long as the star has enough hydrogen to fuse helium
Frame of reference?
The objector place from which the motion is determined
Scalar quantities?
Quantities such as mass, volume, speed, ect. which can be completely be specified by magnitude and has no direction
Vector quantities?
Quantity such as velocity that has both magnitude and direction
Displacement?
Position after changes
Motion?
Change in position of an object when compared to a reference point. All motion is relative to the observer’s frame of reference
Speed?
Scalar quantity
Acceleration?
How quickly an object changes its velocity. That is, the change in velocity divided by the change in time
Free fall?
The movement of an object toward earth solely because of gravity
Friction?
Force that slows an object
Force?
Push or pull upon an object resulting from its interaction with another object
Balanced force?
Combine forces, produce net force of zero. Unlimited number of forces can act on an object to create zero
Unbalanced force?
The forces don’t equal zero, one side has more force
Friction?
Force that opposes motion between two surfaces that are touching each other
Newton’s first law?
An object in motion will remain in motion, an object at rest will remain at rest unless acted upon by an unbalanced force?
Newton’s second law?
F=ma
Momentum?
Quantity of motion of a moving body, measured as a product of mass and velocity
Newton’s third law?
Every action has an equal and opposite reaction
Law on conservation?
Loss of momentum in one object = gain of momentum in another object, momentum is conserved
Energy?
The ability or capacity to do work. Energy can change forms, measured in joules
Kinetic energy?
Energy of motion
Potential energy?
Energy stored due to position
Total energy?
Energy associated with motion and position of everyday objects
Law of conservation of energy?
Law that states that energy cannot be created or destroyed, can be changed from one form to another or transferred from one object to another
What is the big bang theory?
- The universe started to have a few particles and expanded from there
- Redshift supports this theory
- Redshift proves that the wavelength is increased as the object moves farther away from the observer
How does CBM help us?
Radiation, they show us when the universe first happened
What is spectroscopy?
- Way of studying light coming from some material or passing through some material
- Can tell is what is in the light
- Continuous spectrum
- Absorption lines- missing wavelengths
- Emission lines- identify whats happening on the star
What size waves does electromagnetic energy travel through?
Short and long
What does the earth protect us from?
Certain types of waves and radiation
Do waves have mass?
No
Mechanical waves =
Sound waves
The higher the amplitude the more…
Energy it holds
Electromagnetic waves require a…
Medium
What is a vacuum?
The velocity of the electromagnetic wave and the medium
What happens to the wavelength when there is more energy?
It gets shorter
Which color has the longest wavelength and has the least amount of energy?
Red
Which color has the shortest wavelength and has the most amount of energy?
Purple
What two properties do electromagnetic waves exhibit?
- Waves
- Particles
Are photons apart of electromagnetic wave particles?
Yes
Do longitudinal waves travel in the same direction?
Yes
Electromagnetic waves travel?
Perpendicular
On the EM spectrum what wave has the least amount of energy?
Radio
On the EM spectrum what wave has the most amount of energy?
Gamma
List the waves on the EM spectrum from least to greatest?
- Radio
- Microwave
- Infrared
- Visible
- Ultraviolet
- X- ray
- Gamma
Hotter object has?
- Higher energy
- Shorter wavelength
Cooler object has?
- Lower energy
- Longer wavelength
Equation for atoms?
Electrons + Photons + Neutrons = Atoms
Proton have what kind of charge?
Positive
Electrons have what kind of charge?
Negative
Neutrons have what kind of charge?
Neutral
What do electrons occupy?
The space around the nucleus
What provides info for light?
Fingerprints
What emits a continuous spectrum?
Sun and stars
Every element has a unique what?
Emission spectrum
What results in absorption and emission spectra?
Electrons of the atoms gain or lose energy
What does the spectra tell us?
- Chemical composition
- Temperature
- Movement
- Magnetic fields
What does the Nebula consist of?
- 70% hydrogen
- 28% helium
- 2% heavier elements
Is the universe expanding?
Yes! Why?
- The universe cooled before CMB occurred(380,000 years after the big bang)
- Initially no light in the world
- CMB supports the big band
- Universe reached a high density state and then began expanding
- Singularity- universe before expansion
- The universe started expanding 13.7 billion years ago
Speed?
How fast you are moving
Velocity?
Specifies how fast and where you are going
What quantity is velocity?
Vector
What quantity is speed?
Scalar
Methods of acceleration?
- Speeding up (positive)
- Slowing down (negative)
- Turning (changing direction)
Acceleration of gravity on earth?
9.8 m\s\s
Balanced forces?
- Equal in size
- Opposite directions
- Produces a net force of 0
Unbalanced force?
- Unequal in size
- Same direction
- No net force of 0
Mass never…
Changes
Weight can…
Change
Mass is a measure of…
Inertia
Weight is a measure of…
Force of gravity acting on an object
The Doppler Effect?
The apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer
Infrence?
A logical conclusion based on observations
Particle?
Point- like object with no internal structure, just properties of mass and velocity
How is sound discovered?
Change in air density
How is a wave produced?
Then the medium is disrupted
How is the speed of propagation determined?
By speed
In what media does sound travel faster? why?
Dense media because atoms are closer together
What media is light slower in? why?
Dense because the ripple interferes and that slows the group velocity
Propagate?
Waves moving
Equilibrium?
Medium at rest
Sound wave?
Vibration that propagates through matter
Periodic?
Waves on repeat
What creates a waves velocity?
Frequency and wavelength
Specular reflection?
Clear mirror image
Total internal reflection?
Light will only reflect
Trough?
On full wave (above and below medium once)
What is the only wave humans can see on the spectra?
Visible light (all spectrum colors)
Ionizing?
Waves with high energy
Atmospheric windows?
Waves that pass through the atmosphere
New medium (refraction)
Wave enters new medium at an angle and the velocity changes due to the change in density which causes a bend in the normal
Spectrum?
When the rainbow is separated
Spectra?
More than one spectrum
Continuous spectrum?
All colors are in the spectrum
Stellar evolution?
- Gas + dust(forced together by gravity) = star
- Dead star releases dust that will be used to form another star
Stars?
Most plentiful object in the visible universe (hottest blue(k) coolest red(m))
HR Diagram order?
- O
- B
- A
- F
- G
- K
- M
HR Diagram?
Designed by Hertzsprung- Russell
HR Diagram- graph that illustrates relationship between average surface temp of a star and their absolute magnitude
What is supernova responsible for?
The universes disappearing element
Absolute magnitude?
Brightness of stars if they were all the same distance from earth
Apparent magnitude?
Measured brightness procieved from earth
Hubble Laws?
Shows galaxies are receding away from us with a velocity that is proportional to their distances from us
What did CMB form?
The first atoms
Blue shifting?
The decrease in wavelength, with a corresponding increase in frequency of an electromagnetic wave
