Physics - Post-UTME Study Guide
Physics in the Post-UTME tests mechanics, waves, electricity, optics and heat. Many items are one-step applications of a formula, so correct units and vector direction matter.
Core rules
- Equations of motion: v = u + at; s = ut + ½at²; v² = u² + 2as.
- Newton's second law: F = ma; weight = mg.
- Work = force × distance moved in the direction of the force; power = work ÷ time.
- Ohm's law: V = IR; in series, current is the same and resistance adds; in parallel, voltage is the same and 1/R = 1/R₁ + 1/R₂.
- Wave equation: v = fλ.
- Heat: Q = mcΔθ, where c is specific heat capacity.
Worked example
A car accelerates uniformly from rest to 20 m/s in 5 s. Find its acceleration and distance travelled. Acceleration a = (v − u)/t = (20 − 0)/5 = 4 m/s². Distance s = ut + ½at² = 0 + ½ × 4 × 5² = 50 m. The reasoning uses the definition of acceleration first, then the displacement equation for uniform acceleration.
Traps
Convert km/h to m/s by dividing by 3.6 before substituting. Do not treat mass and weight as the same. In series circuits, do not add voltages as if they were parallel branches. In waves, frequency is set by the source and does not change when the wave enters a new medium; speed and wavelength do.