Physics 30 Diploma flashcards
Physics 30 Diploma · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Momentum
- The product of an object's mass and velocity, p = mv. It is a vector quantity pointing in the direction of motion, measured in kg·m/s.
- Impulse
- The product of net force and the time interval over which it acts, J = FΔt. Impulse equals the change in momentum, measured in N·s.
- Conservation of momentum
- In an isolated system with no net external force, the total vector momentum before an interaction equals the total vector momentum after it.
- Elastic collision
- A collision in which both total momentum and total kinetic energy are conserved. Objects separate after impact with no permanent deformation or thermal energy loss.
- Perfectly inelastic collision
- A collision in which the objects stick together and move with one common velocity. Momentum is conserved but maximum kinetic energy is lost.
- Work–energy theorem
- The net work done on an object equals its change in kinetic energy: W_net = ΔKE = ½mv_f² − ½mv_i².
- Coulomb's law
- The electrostatic force between two point charges is F = kq1q2/r², proportional to the product of charges and inversely proportional to the square of their separation.
- Electric field strength
- The force per unit positive charge at a point, E = F/q, a vector pointing in the direction of force on a positive test charge.
- Electric potential energy
- The energy stored in a system of charges due to their positions; for two point charges, PE = kq1q2/r, negative for opposite charges.
- Magnetic force on moving charge
- A charge moving in a magnetic field experiences force F = qvB sinθ, perpendicular to both velocity and field; zero when motion is parallel to the field.
- Magnetic force on a wire
- A current-carrying conductor in a magnetic field experiences force F = BIL sinθ, maximum when the current is perpendicular to the field.
- Electromagnetic induction
- A changing magnetic flux through a loop induces an emf in the loop, described by Faraday's law; the induced current opposes the change by Lenz's law.
- Magnetic flux
- The product of magnetic field strength and the perpendicular area it passes through, Φ = BA cosθ, measured in webers (T·m²).
- Faraday's law
- The induced emf in a loop equals the negative rate of change of magnetic flux through it: ε = −NΔΦ/Δt.
- Lenz's law
- An induced current flows in a direction whose magnetic field opposes the change in flux that produced it, consistent with conservation of energy.
- Accelerating voltage
- A charge q accelerated through potential difference V gains kinetic energy qV; for electrons, qV = ½mv² determines final speed.
- Millikan oil-drop experiment
- Balanced charged oil droplets between horizontal plates so electric force equaled gravitational force, allowing measurement of the elementary charge e = 1.60 × 10⁻¹⁹ C.
- Photon energy
- The energy of a photon is E = hf = hc/λ, where h = 6.63 × 10⁻³⁴ J·s; shorter wavelength means higher energy.
- Photoelectric effect
- Light above a threshold frequency ejects electrons from a metal surface; maximum kinetic energy is K_max = hf − W, independent of intensity.
- Work function
- The minimum energy needed to remove an electron from a metal surface, W = hf₀, where f₀ is the threshold frequency.
- de Broglie wavelength
- Moving particles have wave character with wavelength λ = h/p = h/(mv), explaining electron diffraction and quantized atomic energy levels.
- Bohr model transitions
- An electron dropping from a higher to lower energy level emits a photon of energy E = E_i − E_f = hf; absorption requires a matching energy.
- Line spectra
- Atoms emit or absorb only specific photon energies, producing discrete spectral lines that serve as fingerprints of each element.
- Mass–energy equivalence
- Mass and energy are interchangeable through E = mc²; mass defect in a nucleus appears as released binding energy.
- Binding energy
- The energy required to separate a nucleus into its individual nucleons; it equals the mass defect times c², measured in MeV.
- Alpha decay
- A nucleus emits an alpha particle (helium-4 nucleus), decreasing mass number by 4 and atomic number by 2: (A,Z) → (A−4, Z−2) + α.
- Beta negative decay
- A neutron converts to a proton, emitting an electron and antineutrino; mass number unchanged, atomic number increases by one.
- Gamma decay
- An excited nucleus releases a high-energy photon without changing its mass number or atomic number; it accompanies other decays.
- Half-life
- The time for half the nuclei in a radioactive sample to decay; after n half-lives, remaining fraction is (½)ⁿ.
- Activity
- The decay rate of a radioactive sample, A = ΔN/Δt, measured in becquerels (decays per second); activity halves each half-life.
- Refraction and Snell's law
- Light bends when crossing between media: n₁ sinθ₁ = n₂ sinθ₂, where n = c/v is the index of refraction of the medium.
- Total internal reflection
- When light travels from denser to less dense medium beyond the critical angle θ_c = sin⁻¹(n₂/n₁), it reflects entirely back into the denser medium.