PHYSICS Flashcards
Wave Speed
Wave speed (m/s) = Frequency (Hz) x Wavelength (m)
Reflection
Angle of incidence = Angle of reflection
Density
Density (kg/m3) = Mass (kg) / Volume (m3)
Efficiency
Efficiency = Useful energy out / Total energy in
Alpha Decay
Mass number decreases by 4, atomic number decreases by 2 (2 protons, 2 neutrons lost). Alpha particle (4/2) released
Beta Decay
Mass number constant, atomic number increase by 1 (1 neutron turns into 1 proton). Beta particle (e-) released
Velocity
v = s / t
Acceleration
a = (v-u) / t
Gravity Force (Weight)
W = mg
Force
F = ma, F = △mom / t
Work done
Work done (j) = Force (N) x Distance (m)
Power (energy and force)
Power (W) = Work done (j) / Time (s)
Pressure
Pressure (Pa) = Force (N) / Area (m2)
△Gravitational Potential Energy
△Gravitational Potential Energy = Mass (kg) x △Height (m) x Gravitational field strength
Kinetic energy
Kinetic energy (j) = 0.5 x Mass (kg) x Speed2 (m2/s2)
Momentum
Momentum (kjm/s) = Mass (kg) x Velocity (m/s)
Power (electricity)
P = IV, P = I2R, P = V2/R
Charge, Current, Time
Q = It
Energy Transfered, Charge, P.d
E = QV
P.d, Current, Resistance
V = IR
Total Resistance (2 in parallel)
Rt = Product / Sum
Total Resistance (identical in Parallel)
Rt = R1 / n
Transformer Equation
V1 / V2 = Turns1 / Turns2
Resistance, P.d relationship (in series)
R1 / R2 = V1 / V2
Current, Resistance and P.d (in series)
I1 = I2 = I3, Vt = V1 + V2, Rt = R1 + R2
Current and P.d (in parallel)
It = I1 + I2, V1 = V2 = V3
Energy
= ItV (current x time x voltage)
Magnetic Force
Magnetic field x Current x Length (BIl)
Elastic Potential Energy
0.5 x Spring Constant x e (extension/length) (0.5ke)
Specific Heat Capacity
thermal energy / mass x delta temperature
Hydrostatic Pressure
depth (height) x density x gravity (pgh)
Frequency
1 / Period
