PHYSICS Flashcards
Studies force and motion
Mechanics
studies light (mirrors and lenses)
Optics
Study of relationship of heat, mechanical energy and energy transfer
Thermodynamics
Study of electricity, magnetism, and electromagnetic fields
Nuclear physics
Seven fundamental quantities
time (s) length (m) mass (kg) temp (K) electric current (A) amount of substance (mol) luminous intensity (cd)
If 2 vectors have the same direction, they are
parallel
If 2 vectors have the same magnitude in the same direction, they are
equal
If a vector is equal to the magnitude of the other but in opposite direction, they are
antiparallel
Newton’s laws of motion
- An object at rest will stay at rest, and an object in motion will stay in motion unless acted upon by an unbalanced force
- F=ma
If a net external force acts on a body, the body accelerates. The direction of acceleration is the same as the direction of the net force. The net force vector is equal to the mass of the body x acceleration of the body (F=ma) - For every action there is an equal and opposite reaction
Pythagorean theorem
x^2+y^2=z^2
Vector addition theta formula
0 = tan^-1 (Ay+By / Ax+Bx)
Types of forces
contact
noncontact
The force exerted by a surface to a body in contact which tends to oppose the motion of the object
The direction is always parallel to the surface and against the direction of the relative motion
Friction
Types of friction
Static friction force
Kinetic friction force
Spring force
Spring formula
F=kx
- k is the spring constant
- x is the displacement
Newton’s law of gravitation
Fg= G (m1m2/r)
What is the value of the gravity constant
6.67x10^11
Linear motion formulas
Vf = Vi +at
d = (Vf+Vi)/2 (t)
d = Vit+1/2at^2
V^2 = vi^2 + 2ad
A particle moving near the earth’s surface under the influence of its weight
Projectile
Remember - projectile motion equations
v1x = (v1)cos0 a1x = 0 vx =(v1x) x = (v1x)t v1y = v1(sin0) a1y=-g vfy = v1y - gt y = (v1x)t - 1/2 gt^2
Centripetal acceleration
a = v^2/r
Formula for kinetic energy
KE = 1/2 mv^2
We body moves a distance along a straight line while a constant force is applied
Work
The unit of work
Joules (Nm)
True or false
When force and displacement are perpendicular the force does no work
True
Work energy theorem
W = change in KE
The rate at which work is done
Power
Unit of power
Watt
p=w/t
Formula for impulse
I = Ft
Impulse momentum principle
The impulse acting on an object produces a change in momentum of the object that is equal in both magnitude and direction to the impulse
A brief force between two objects causes the object to move in opposite direction
Recoil
Perfectly inelastic collision
Stick together after collision
Elastic
Did not stick together
Energy is conserved
Partially inelastic
Did not stick together
Energy is lost
The total kinetic energy after the collision is less than that before the collision though the total momentum is conserved
Formula for momentum
p=mv
If the change in momentum of one body is exactly the negative of the other number then the change in the total momentum must be zero
True
Rules of conservation of momentum
The total momentum of an isolated system is constant or conserved
More generally if there are external forces but the vector sum of all external forces is zero the total momentum is constant
Formula for elastic collision
(m1a)(v1a) + (m1b)(v1b) = (m2a)(v2a) + (m2b)(v2b)
Formula for inelastic collision
(m1a)(v1a) + (m1b)(v1b) = (m1a+m1b) v2
Formula for stress
Stress = Force/Area
Formula for strain
Strain = deformation/length
Young’s modulus of elasticity
YME = [(F)(L)] / [(A)(deformation)]
Formula for density
p=mv
What is the densest material found on earth?
Osmium 922,500kg/m^3)
The ratio of density of a substance to the density of water at 4 degrees celsius
Specific gravity
Unit for pressure
Pascal
Types of waves
Transverse
Longitudinal
Periodic
Sinusoidial
Periodic waves with simple harmonic motion
Sinusoidal wave
The length 1 complete wave pattern
Wavelength
Formula for wave speed
wave speed = (frequency)(wavelength)
frequency = 1/Time
The result of two or more waves passing through the same region at the same time
Interference
It is an interference phenomenon formed as a result of the perfectly timed interference of two waves passing through the same medium
Standing wave pattern
A point that never moves during wave motion
Node
A point with maximum amplitude of motion between two nodes
Antinode
When an applied force varies with the same frequency as a normal mode frequency the amplitude of oscillation builds up. In normal-mode motion the every particle vibrates sinusoidally with the same frequency
Resonance
Sound travels ___ times faster in solid and ____ faster in liquid than in gas
15
Four
The simplest sound waves which have definite frequency amplitude and wavelength
Sinusoidal waves
It is determined by the frequency of the sound
The quality that lets us determine if the sound is high or low
Pitch
It is the logarithmic intensity scale
Decibel scale
A frequency shift caused by motion of a source of sound or listener relative to the air
When the source of sound in the listener are in motion relative to each other the frequency of the sound heard by the listener is not the same as the source of frequency
Doppler effect for sound
The angle of reflection is equal to the angle of incidence for all wavelengths and for any pair of materials
Law of reflection
What is the other term for the law of refraction
Snell’s law
Interference patterns when light passes through an aperture or around an edge
Diffraction
If outgoing rays do not actually pass through the image point
Virtual image
If outgoing rays do 6:00 pass through the image point
Real image
Consists of charges in one motion from one region to another
Electric current
Conducting path that forms a closed loop
Electric circuit
Any motion of charge from one region to another
Current
These have resistance intermediate between those of metals and those of insulators
Semiconductors
Ratio of potential difference or voltage to total current in ohms
Resistance
The real content is a direct proportion and proportionality of voltage to current but can only be applied for constant r
Ohm’s law
Formula of current for series connection
I = I¹= I² = I³
Formula for current of parallel connections
I = I¹ + I² + I³
Formula for potential difference of series connection
V = V¹ + V² + V³
Formula for potential difference of parallel connections
V = V¹ = V² = V³
Formula for resistance of series connection
R = R¹ + R² + R³
Formula for resistance of parallel connection
R = 1/R¹ + 1/R² + 1/R³
The quantitative description of hotness and coldness measured by a thermometer
Temperature
Formula for converting fahrenheit to degrees
°F = 1.8 (°C) + 32
Formula for converting fahrenheit to degrees
°F = 1.8 (°C) + 32
Formula for converting degrees celsius to degrees fahrenheit
°C = 0.56 (°F - 32)
Formula for converting Kelvin to degrees Celsius
K = °C + 273.15
The state at which two bodies attain the same temperature
Thermal equilibrium
How much force is needed to stop or turn a moving object
Momentum
Formula for momentum
P=mv
Types of friction
- static
- sliding
- rolling
- Fluid
Gravitational energy due to the object’s position relative to the earth
Gravitational potential energy
Affected by the objects amount of deformation and stiffness
Strain potential energy
Formula for gravitational potential energy
GPE = mgh
Formula for stiffness
K = stiffness/spring constant
A brief force between two objects that causes the objects to move in opposite directions
Recoil
Formula for recoil
(m¹+m²)v¹ = (m¹v¹)+(m²v²)
These waves do not need matter to transfer energy
is considered a transverse wave because it has similar characteristics and parts
Electromagnetic waves
Examples: radiation, microwaves, x ray
A measure of how many waves go past the point in one second
Frequency
Formula for frequency
f = 1/T
A measure of how far the medium moves from the rest position
Amplitude
The energy of a wave is proportional to the square of its amplitude
E = CA²
The wave enters a new medium and its speed changes
Refraction
The bending of waves around an object
the amount of bending depends on the size of the obstacle and the size of the waves
Diffraction
The larger of cycle the smaller the wavelength the ________the diffraction
Lower
The smaller the obstacle in the larger the wavelength
The larger than the fraction
Measures how high or low the sound seems to be to a person
Pitch
How loud or soft a sound is
Loudness or amplitude
How many decibels should be added to double the loudness of a sound
20 decibels
Sound waves with frequencies above the normal human hearing range
Ultrasound
20 - 100 khz
Sounds with frequency below the normal human range of hearing
Infrasound
20 to 200 hz