Exam 2 Vocab Flashcards
What is the Universal Law of Gravity?
A body attracts another body with a force directly proportional to the product of their masses and indirectly proportional to square the distance separating them
What is projectile motion?
A split curve path that is composed of horizontal and vertical motion
What is the acceleration of a satellite with a circular motion?
0, speed doesn’t change
What happens to speed, acceleration, force of gravity with elliptical orbit?
Speed decreases as you get farther away, and force of gravity increases its speed as it comes in
What is escape speed?
What an object has insufficient speed to remain in orbit, crash back to earth
What is buoyancy?
The force of the weight displaced
density = ?
mass/volume
When does an object float?
when the weight of the fluid displaced equals the weight of object
How does an object’s apparent weight change when submerged?
Principle?
Because of the Archimedes’ Principle: “An immersed body is buoyed up by a force equal to the weight of the fluid it displaces.”
What is Boyle’s Law?
P1 x V1 = P2 x V2
What is Charles Law?
V1/T1 = V2/T2
What is Pascal’s principle?
Pressure in = pressure out
What is Bernoulli’s principle?
As the speed of a fluid increases, internal pressure in the fluid decreases
A1V1 = A2V2
What is thermal energy?
The translational kinetic energy within a substance
What is translational kinetic energy?
atoms bumping into each other
What is temperature?
measures the average thermal energy using some arbitrary scale
What is heat?
The transfer of thermal energy from one object to another (Q)
What is thermal equilibrium?
The transfer back and forth ceases because average is the same
What are the big ideas of the laws of thermodynamics?
- energy is neither created nor destroyed
- heat will flow from hot to cold (entropy/order)
- entropy (lack of order) is 0 at 0 Kelvin
What is heat capacity?
The amount of heat needed to increase a unit of mass by 1 degree C (variable is c)
What is thermal expansion?
Density and heat capacity change with temperature
- as temp goes up, density goes down
- most solids are more dense (except water)
What is thermal conduction?
occurs through the collisions of particles (high to low energy)
What is a conductor?
allows rapid transfer of heat
What is an insulator?
transfers heat slowly
What is convection?
occurs through the flow of a fluid due to temperature difference
What is radiation?
the emission of energy in the form of light
What is the greenhouse effect?
IR light gets trapped in greenhouse gas, keeping the earth from being too hot
Solid –> gas
Solid –> liquid
Liquid –> gas
Gas –> liquid
Gas –> solid
Liquid –> solid
Solid –> gas (Sublimation)(+)
Solid –> liquid (Melting)(+)
Liquid –> gas (evaporation)(+)
Gas –> liquid (condensation)(-)
Gas –> solid (deposition)(-)
Liquid –> solid (freezing)(-)
What is the heat of fusion?
The energy required for a substance to transition from solid to liquid
What are waves?
traveling vibrations
What is the amplitude? Wavelength? Frequency? Period?
Amplitude- Hight from crest
Wavelength- length from crest to crest
Frequency- # waves per second
Period- time per wave
Transverse vs. Longitudinal wave
Transverse: vibration is perpendicular to direction of wave (up & down)(waves)
Longitudinal: compressions and expansions that are parallel to direction (sound)
Types of interference
Interacting with each other:
1. constructive: amplifies
2. destructive: diminishes
What is the Doppler Effect?
Ripple of frequency changes (like an egg) as an object moves
What are harmonics?
whole # multiples of the fundamental; has nodes
What is speed of light in a vacuum?
All types of electromagnetic radiation have same speed in vacuum (c= 3.00 x 10.00^8 m/s)
Does speed of light in a medium vary based on frequency?
yes, as wavelength increases, frequency decreases
Describe the electromagnetic spectrum
low f, high wavelength
IR, Visible [ROY G BIV], ultraviolet
low wavelength,high f
f and E are proportional
Are radio waves and microwaves high or low energy? X-rays and gamma rays?
radio and microwave- low
x-rays and gamma rays- high
Transmission vs absorption vs reflection
Transmission: lets light pass (transparent)
Absorption: takes in light
Reflection: light in = light out
What is refraction?
Bending/ altering of view of an object (fish under water)
Relate refractive index to speed of light in a medium
speed of light = c/refractive index
slower light, larger index, more bending
medium changes speed
Which wavelengths of light are refracted most, long or short?
Short
What is diffuse reflection?
reflection from a rough surface, so it disperses light
What is dispersion?
separation of different frequencies of light causes different colors
- shorter wavelength of light tends to be slowed down more by a medium
Describe importance of Ozone layer
Acts as a protective layer against UV light (toxic)
