Worked examples: SACE Stage 2 Physics Formula Sheet

Selected worked examples

1. Motion · impulse

   Formula or reference: For a constant net force, J = FΔt = Δp.

   Units and conditions: Use N and s for impulse in N s. Include its direction.

   Worked example: A 6.0 N net force east for 0.30 s changes momentum by 1.8 kg m/s east.

2. Light · energy from wavelength

   Formula or reference: E = hc/λ

   Units and conditions: Use wavelength in metres to calculate energy in joules.

   Worked example: A 500 nm photon has energy about 3.97 × 10⁻¹⁹ J.