AS Physics 2020 Flashcards
Define accuracy
How close a measurement is to the true value
Define precision
How close measurements are to each other.
How many significant figures it is measured to.
How to calculate uncertainty when adding or subtracting measurements?
Add the uncertainties of each value.
How to calculate uncertainty when multiplying or dividing measurements?
Add fractional uncertainties of values and multiply the sum of these uncertainties by the result.
How to calculate percentage uncertainty?
(uncertainty÷measured value)x100
How to calculate relative uncertainty?
uncertainty÷measured value
Give 4 examples of vector quantities
Velocity
Acceleration
Weight
Displacement
Give 4 examples of scalar quantities
Density
Speed
Distance
Volume
The gradient of a displacement-time graph gives the _________
velocity
The gradient of a velocity-time graph gives the _________
acceleration
The area under a velocity-time graph gives the _________
displacement
The gradient of a acceleration-time graph gives the _________
change in velocity
List the 4 suvat equations
v=u+at
s=(u+v)/2 x t
s=ut+½at²
v²=u²+2as
At terminal velocity, weight is equal to ______
air resistance.
Momentum formula
Momentum=massxvelocity
Conservation of linear momentum formula
m₁v₁ + m₂v₂ = m₁v₁ + m₂v₂
Elastic collision rule
Total Kinetic energy before collision = total kinetic energy after collision.
Inelastic collision rule
Total kinetic energy before collision > total kinetic energy after collision.
Newton’s 1st law
Object will remain stationary or in constant motion unless acted upon by another force.
Newton’s 2nd law
F=ma i.e net force applied is proportional to acceleration
Newton’s 3rd law
Every action has an equal and opposite reaction
Impulse formula
Δp = FΔt = mv - mu
Upthrust in fluid formula
upthrust = hρgA = ρgV
Torque or moment of force formula
τ = Fdsinθ
Conditions for equilibrium
Στ = 0 ΣF = 0
Work done by a force formula
ΔW = Fs x cosθ
Work done in stretching a spring formula
ΔW = ½kx²
Electrical potential energy formula
V = W/q
Power in terms of work done formula
P = W/t = Fv
Electric field intensity formula
E = V/d
Current in terms of charge formula
I = Q/t
Ohm’s law formula
R = V/I
Voltage in terms of charge formula
V = Energy/Q
e.m.f formula
e.m.f = lost volts + terminal p.d.
Resistivity formula
R = ρL/A
Power definition
P = Energy/time
When temperature of thermistor increases, resistance ________
decreases
When Light around a LDR increases, resistance
decreases
What are kirchoff’s laws
ΣI = 0 ΣEMF = ΣIR
Stress formula
σ = F/A
Strain formula
ε = x/L
Young modulus formula
E = σ/ε
What is a wavelength
Distance between 2 crests or 2 toughs
What is frequency of wave
Number of waves in 1 second
What is time period of a wave
Time taken for 1 complete wave osscilation
What is the speed of a wave
The distance moved by the wave in 1 second
What is the amplitude of a wave
The maximum displacement of particles in a wave
What are coherent waves
Two waves with the same frequency and constant phase difference
Intensity of a wave formula
I∝a² (I is intensity, a is amplitude)
What is constructive interference of waves
When the crests and troughs of 2 different waves overlap each other, amplitudes become added.
What is destructive interference
When the crests of 1 wave overlap the troughs of another, the amplitudes cancel each other.
What is the formula from the double slit experiment
x = (nλD)/d
x is distance of nth fringe from centre
n is the order of fringe counting from centre
d is the distance between slits
D is the distance between screen and slits
What is the formula for diffraction gratings
nλ=dsinθ
What is the strong force
Acts between nucleons and holds them together. Has a very short range.
Those affected by the strong force are called ____
hadrons
Those not affected by the strong force are called _____
leptons
What is a fundamental particle
A particle that cannot be split into anything smaller e.g. electron
What is the charge and strangeness of an Up quark
Charge: +⅔
Strangeness: 0
What is the charge and strangeness of an Down quark
Charge: -⅓
Strangeness: 0
What is the charge and strangeness of an Strange quark
Charge: -⅓
Strangeness: -1
What are the 4 leptons
Electron
Positron
Electron neutrino
Electron antineutrino
What are 2 hadrons
Protons
Neutrons
Define mass of a body
property of the body resisting changes in motion
Define force
rate of change of momentum