Physics Flashcards
What are the units of force?
N (kg⋅m/s^2)
What are the units of work/energy?
J (kg⋅m^2/s^2)
What are the units of power?
W (kg⋅m^2/s^3)
What are the units of velocity?
m/s
What are the units of acceleration?
m/s^2
What are the units of density?
kg/m^3
What are the units of electric field
N/C
What are the units of current?
C/s
Vector vs. scalar?
Vector: quantity that has magnitude and direction (displacement, velocity etc.)
Scalar: quantity that has magnitude only (distance, speed etc.)
How do you add vectors?
Tip to tail (place tip of A to tail of B, then line from tail of A to tip of B)
X vector component vs. Y vector component? Pythagorean?
x = vcosθ
y = vsinθ
If given x and y: x^2 + y^2 = v^2
Displacement vs. distance? Graph?
Displacement: vector quantity, accounts for only the net traveled (final - initial)
Distance: scalar quantity, accounts for total pathway
Area under curve of v vs. t graph
Velocity vs. speed? Equation?
v = Δx/Δt
Forces are vectors or scalars? Gravitational, equation? Friction, equation? Normal?
Forces are vectors
Gravitational force is an attractive force Fg = Gm1m2/r^2
Frictional force opposes the movement of objects Ff = μkN
- static: for stationary objects (μs > μk)
- kinetic: for moving objects
Normal force is the component of force b/w objects that is perpendicular to plane of contact
What is acceleration, equation?
Vector quantity, result of a net force applied a = Δv/Δt
Mass vs. weight?
Mass: scalar quantity that is the measure of matter in an object
Weight: vector quantity that is the measure of the gravitational force on a mass Fg = mg where g = 10m/s^2
What is Newton’s First Law? Second Law? Third Law?
First: F = ma, an object at rest or in motion at constant velocity will remain unless a net force is applied
Second: acceleration only occurs when there is a net force
Third: Force of A on B = - Force of B on A, action/reaction with equal but opposite force between objects
What are the two main linear kinematic equations? What about time up, time down, max height?
v = v0 + at
Δx = v0t + 1/2at^2
time up = time down
@max height, v = 0
What is centripetal force?
Force in the radial direction to prevent objects from spinning out Fc = mv^2/r
What is the torque equation?
τ = rFsinθ, CW is (-), CCW is (+)
What is energy? Kinetic energy? Potential energy, gravitational + elastic? Conservation?
KE = 1/2mv^2
Gravitational PE = mgh
Elastic PE = 1/2kx^2
Wnc = KE + PE (so usually KE = PE, if no friction)
Conservative vs. non-conservative forces?
Conservative: path independent, doesn’t dissipate energy
Non-conservative: Friction (heat)
What is work, equation? P-V equation?
W = Fdcosθ (angle of OBJECT movement)
W = PΔV or area under curve of P-V graph
Work done by a system is (+)
Work done on a system is (-)
What is power, equation?
P = W/Δt = F⋅v
What is mechanical advantage, equation? Efficiency?
ME = F out, without machine / F in, with machine
Efficiency = W out / W in
What is temperature? K vs. C? Heat?
Temp is proportional to the average KE
K = C + 273, 0 K is considered absolute zero
Heat is the transfer of thermal energy b/w objects
Isolated vs. closed vs. open system?
Isolated: no exchange of energy or mass
Closed: exchange of energy but not mass
Open: exchange of both mass and energy
What is the internal energy equation or first law of thermodynamics?
ΔU = Q - W
U = internal energy of system, (+) when temp increases
Q = heat energy, (+) when heat enters system
W = work, (+) when work is done by system
Conduction vs. convection vs. radiation?
Conduction: transfer of heat through direct contact of objects and molecular collisions
Convection: transfer of heat by physical motion of a fluid over a material (liquids, gases)
Radiation: transfer of heat by EM waves
What is the specific heat equation?
Q = mcΔT
What are the different phase changes? Temperature they occur at? Equation?
Solid –> liquid: melting/fusion
Liquid –> gas: vaporization
Gas –> liquid: condensation
Liquid –> solid: freezing
Solid –> gas: sublimation
Gas –> solid: deposition
Phase changes occur at a constant temperature
Q =mL
L = latent heat
Isovolumetric (isochoric) vs. isothermal vs. isobaric vs. adiabatic
Isovolumetric (isochoric): at a constant volume
Isothermal: at a constant temperature
Isobaric: at a constant pressure
Adiabatic: no heat exchange (steeper than isothermal on a P-V graph)