Phys - Unit 3 Flashcards
KILL EVERYONE
Relative Atomic Mass
System to measure mass where 1 = the mass of one nucleon
hydrogen has a Mr of 1
Unified Atomic Mass Unit
u = 1.66x10^-27 kg = 1Da
Molar Mass
System to measure mass where 1mol = number of atoms in 12g of C-12 = 6.02x10^23
Molar mass of C-12 is 12gmol^-1
Ideal Gas Assumptions
NISCER
Negligible volume
Intermolecular forces
Straight lines
Constant motion
Elastic collisions
Random distributed energy & motion
Relationship between V & p (boyles)
1/V ∝ p
p1V1 = p2V2
Relationship between V & T (charlie)
V ∝ T
V1/T1 = V2/T2
Relationship between p & T (gay)
p ∝ T
p1/T1 = p2/T2
pV & Energy Equations
pV = nRT
= NkT
= 1/3 Nmc^2
Ek = 3/2 pV
Deriving pV = 1/3 Nmc^2
- Draw container and label all side lengths & mass and velocity of a particle
- Momentum change & time taken between wall collisions
- Find pV
- Velocity can be in any direction, so find c = sqrt(vx^2 + vy^2 + vz^2)
- On average, only 1/3 particles will travel in one plane.
pV = 1/3 Nmc^2
Internal Energy
deltaU = Q - W
U = ΣEk + ΣEp, but ΣEp = 0 for ideal gases
Mass Defect
Difference between predicted and actual mass of particles
Binding Energy
E = [mass_defect]c^2 gives the energy needed to dissociate a nucleus into its constituent nucleons.
Amplitude
Maximum displacement from equillibrium in an SHM system.
Free / Natural Oscillations
Occur when an SHM system is displaced, causing it to return to equillibrium via oscillation.
Resonance
A generator exerts a driving force, which drives oscillation (resonance).
When the driving force frequency is larger or smaller than the natural frequency, less energy is transferred.
When the driving force frequency is equal to the natural frequency, energy transferred is maximised, so the amplitude is maximised too.
Resonant / Natural Frequency
When a system reaches a specific frequency, its amplitude is maximised.
Method For Analysing
- Measure bg radiation with no absorbers
- Measure source radiation
- Measure with paper, add aluminium foil and measure again (and repeat with several meters of concrete in between source and detector)
- If count drops with paper, alpha is present
If count drops FURTHER with aluminium foil, beta is present.
If count is above bg level, gamma is present (drops FURTHER with concrete, gamma is present).
Continuous Decay Rate
N = N₀e^-λt
A = A₀e^-λt
Discrete Decay Rate
N = N₀ / 2^x
A = A₀ / 2^x
Alpha, Beta, Gamma
Alpha is a helium nucleus
Beta is an electron
Gamma is a photon
Bacquerels
A = λN
Force Due To Magnetic Fields and N3L
The magnet that is creating the magnetic field that the current is flowing through experiences an equal and opposite force to the wire.
Hall Voltage
V = Ed
V = Bvd
Linac
Uses alternating electric fields to accelerate particles by alternating the p.d across tubes.
Tubes get longer as the particle speeds up.
Cyclotron
Uses alternating electric fields to accelerate particles by alternating the p.d across dees, while the particles travel in an outward spiral, increasing the radius of circular travel.
Synchrotron
Uses alternating electric fields to accelerate particles by alternating the p.d across circular tubes.
The magnetic flux density increases as the speed of the particles increases
Charging Capacitor
Charge increases
Current decreases (current stops flowing across the capacitor)
Potential Diifference increases (levels with the rest of the circuit)
Discharging Capacitor
Charge decreases
Current decreases
Potential Difference decreases
Doppler Effect Equation
Δλ / λ = v / c
Kepler’s First Law
Objects travel in elliptical orbits
Kepler’s Second Law
Orbits sweep equal areas per any amount of time
Kepler’s Third Law
T^2 = kr^3
