Physics
Physics in the FMRDA Medicine Admission exam covers mechanics, work and energy, momentum, electricity, waves, and optics. The paper favours multi-step numerical problems and conceptual checks, so write the known quantities with units before choosing an equation.
Mechanics and energy
For constant acceleration, use v = u + at, s = ut + ½at², and v² = u² + 2as. Resolve projectile motion into independent horizontal and vertical components: horizontal velocity stays constant if air resistance is ignored, while vertical motion accelerates at g. Newton's second law is Fnet = ma. Work is W = Fs cosθ; kinetic energy is ½mv²; gravitational potential energy near Earth is mgh. Mechanical energy is conserved when only conservative forces act.
Momentum and electricity
Momentum p = mv is conserved in collisions when no external net force acts. In elastic collisions, kinetic energy is also conserved; in inelastic collisions it is not. For circuits, Ohm's law is V = IR. Resistors in series add directly; in parallel, 1/Rtotal = 1/R1 + 1/R2 + … Electrical power is P = VI = I²R = V²/R.
Waves and optics
Wave speed v = fλ. Refraction follows Snell's law, n1 sinθ1 = n2 sinθ2. Light bends toward the normal when entering a denser medium. For a converging lens, 1/f = 1/v + 1/u using the sign convention taught in your syllabus.
Worked example
A ball is launched horizontally at 20 m/s from a height of 45 m. Taking g = 10 m/s² and ignoring air resistance, find the horizontal range. Vertical fall: h = ½gt², so 45 = ½ × 10 × t², giving t² = 9 and t = 3 s. Horizontal range = horizontal speed × time = 20 × 3 = 60 m. The initial vertical velocity is zero, so it does not affect the fall time.
Traps that cost marks
- Mixing up the sign of g or treating downward motion as negative inconsistently.
- Assuming the horizontal and vertical motions affect each other.
- Using total resistance rules for the wrong series/parallel arrangement.
- Forgetting that work done by a force perpendicular to displacement is zero.
- Confusing wave speed with frequency when the medium changes.