Physics - Topic 1 - Key Concepts of Physics

• What is the SI unit for length?

  Metre, m
• What is the SI unit for mass?

  Kilogram, kg
• What is the SI unit for time?

  Second, s
• What is the SI unit for electric current?

  Ampere, A
• What is the SI unit for temperature?

  Kelvin, K
• What is the SI unit for the amount of substance?

  Mole, mol
• What is the SI unit for electric potential difference?

  Volt, V
• What is the SI unit for frequency?

  Hertz, Hz
• What is the SI unit for force?

  Newton, N
• What is the SI unit for energy?

  Joule, J
• What is the SI unit for power?

  Watt, W
• What is the SI unit for pressure?

  Pascal, Pa
• What is the SI unit for electric charge?

  Coulomb, C
• What is the SI unit for electrical resistance?

  Ohm, Ω
• What is the SI unit for magnetic flux density?

  Tesla, T
• What are the prefixes for the following SI units: giga, mega, kilo, centi, mili, micro, and nano?

  • Giga (G): \( \times 10^9 \) (1 billion)
  • Mega (M): \( \times 10^6 \) (1 million)
  • Kilo (k): \( \times 10^3 \) (1 thousand)
  • Centi (c): \( \times 10^{-2} \) (1 hundredth)
  • Mili (m): \( \times 10^{-3} \) (1 thousandth)
  • Micro (µ): \( \times 10^{-6} \) (1 millionth)
  • Nano (n): \( \times 10^{-9} \) (1 billionth)
• What is the equation for calculating distance?

  Distance = speed × time
• What does the equation \( a = \frac{v - u}{t} \) represent?

  It represents acceleration.
• What does the equation \( F = ma \) represent?

  It represents the relationship between force, mass, and acceleration.
• What is the equation for weight?

  Weight = mg
• What does \( \Delta GPE = mg\Delta h \) calculate?

  It calculates the change in gravitational potential energy.
• What is the equation for kinetic energy?

  KE = \frac{1}{2} mv^2
• How is efficiency calculated?

  Efficiency = \frac{\text{useful energy output}}{\text{total energy input}}
• What is the equation for wave speed?

  Wave speed = \( v = f\lambda \)
• What is the equation for work done?

  Work done = force × distance (moved in the direction of the force) = \( E = Fd \)
• How is power calculated?

  Power = \frac{\text{work done}}{\text{time}} = \frac{\text{energy transferred}}{\text{time taken}}
• What does the moment of force equation \( \text{Moment} = \text{force} \times \text{perpendicular distance} \) calculate?

  It calculates the turning effect of a force.
• What is the equation for energy transferred in terms of charge and potential difference?

  Energy transferred = charge moved × pd = \( E = QV \)
• What is the equation for charge?

  Charge = current × time = \( Q = It \)
• What is the relationship between voltage, current, and resistance?

  Voltage = Current × Resistance = \( V = IR \)
• How is electrical power calculated?

  Electrical Power = current × pd = \( P = IV \)
• What is another equation for electrical power?

  Electrical power = current² × resistance = \( P = I^2R \)
• What is the equation for density?

  Density = mass / volume = \( \rho = \frac{m}{V} \)
• What is the equation for force on a spring?

  Force on spring = spring constant × extension = \( F = k\Delta x \)
• What is the equation for pressure?

  Pressure = force / area = \( P = \frac{F}{A} \)
• What is the equation for energy transferred in terms of voltage and time?

  Energy transferred = \( IVt \)
• What is the equation relating primary and secondary voltage and turns in a transformer?

  \( \frac{V_p}{V_s} = \frac{N_p}{N_s} \)
• What is the equation for change in energy in terms of mass and specific heat capacity?

  Change in energy = mass × specific heat capacity × temp change = \( \Delta Q = mc\Delta \theta \)
• What is the equation for energy in terms of mass and specific latent heat?

  Energy = mass × specific latent heat = \( Q = ml \)
• What is the equation for pressure and volume change?

  \( P_1V_1 = P_2V_2 \)