Physics IGCSE year 9

• Pressure


  The force exerted per unit area in a given direction
• Density


  The mass per unit volume of a substance
• Weight


  The force exerted on an object by gravity
• Force


  A push or pull that can cause an object to change its motion
• Velocity


  The rate of change of an object's position
• Moment


  The tendency of a force to cause rotation or twisting
• Momentum


  The product of an object's mass and velocity
• Δp


  The change in an object's momentum due to a force
• Acceleration


  The rate of change of an object's velocity
• Boyle's Law


  The volume of an ideal gas is inversely proportional to the pressure
• Thermal energy


  The energy associated with the motion of particles in a substance
• Pressure (P) = Force (F) / Area (A)


  P = F / A (Pascal's law)
• Density (ρ) = Mass (m) / Volume (V)


  ρ = m / V (-density formula)
• Weight (W) = Mass (m) * Acceleration due to gravity (g)


  W = m * g (weight formula)
• Force (F) = Mass (m) * Acceleration (a)


  F = ma (force formula)
• Moment (M) = Force (F) * Distance (r)


  M = F * r (moment formula)
• Momentum (p) = Mass (m) * Velocity (v)


  p = mv (momentum formula)
• Change in Momentum (Δp) = Force (F) * Time (Δt)

  Δp = FΔt (change in momentum formula)
• Boyle's Law: P1V1 = P2V2


  P1V1 = P2V2 (Boyle's law formula)
• Thermal Energy: 1/2 * Mass (m) * Velocity squared (v^2)


  Thermal Energy = 1/2 * m * v^2 (thermal energy formula)
• Half-Life


  The time it takes for the amount of a radioactive substance to decrease by half.
• Radioactive Decay


  The spontaneous process by which an unstable atomic nucleus loses energy and stability by emitting ionizing radiation.
• Alpha Decay


  Heavy elements decay into lighter elements, releasing 2 protons and 2 neutrons.
• Beta Decay


  Neutron-rich nuclei emit energy to become more stable, increasing atomic number by 1.
• Gamma Decay


  Excited atomic nuclei release excess energy as high-energy photons.