Equations Flashcards
What is the equation for frequency in terms of wavelength?
Frequency (Hz) = Speed of light (ms-1) / Wavelength (m or nm)
What is the speed of light and what is its symbol?
3.0 x 10^8 ms-1
Symbol: c
What is the Planck equation?
Energy (J) = Plancks constant (J) x frequency (Hz)
What is Plancks constant and what is its symbol?
6.63 x 10^-34J
Symbol: h
What is the equation for laser power?
Laser power (W) = Energy (J) / time (s)
What is the equation for Energy in terms of Plancks and wavelength?
Energy (J) = (Plancks constant (J) x speed of light (ms-1) / wavelength (m or nm)
What is the equation for the number of photons in the beam passing a fixed point ach second?
Beam energy / photon energy
Beam energy = Energy (J) = (Plancks constant (J) x speed of light (ms-1) / wavelength (m or nm)
Photon energy = Laser power (W) = Energy (J) / time (s)
What is the equation for energy in terms of mass and speed of light?
Energy (J) = mass (kg) x speed of light^2 (ms-1)
How do you convert J into eV?
1.6g x 10^-19 = 1eV
J / 1.6g x 10^-19 = eV
What is an electronvolt?
The energy gained when 1 electron travels through 1 volt of p.d
What is the equation for specific charge?
Specific charge (CKg-1) = Charge (C) / mass (kg)
What is the charge of a proton/electron?
Proton = +1.6 x 10^-19 Electron = -1.6 x 10^-19
What is the mass of a nucleon?
1.67 x 10^-27
What is the calculation for the energy of one photon?
Energy of one photon = maximum kinetic energy gained by the electron + minimum energy to emit one electron
hf = Ek + O|
How does the Photoelectric effect show that wave must be a particle?
One electron must absorb one photon and so light must also be a particle
