Physics
What the exam tests
Kankor physics covers mechanics (motion, Newton's laws, work and energy, momentum), fluids and pressure, heat and temperature, basic electricity and magnetism (Ohm's law, series and parallel circuits), waves and sound, light and simple optics, and a light touch of modern physics.
Concepts to master
- Kinematics: distinguish velocity from acceleration; use v = u + at and s = ut + ½at².
- Newton's laws: net force causes acceleration; action–reaction pairs act on different bodies.
- Energy and momentum: conservation laws let you skip force calculations.
- Ohm's law V = IR, plus power P = VI; resistors in series add, in parallel add reciprocals.
- Waves: frequency × wavelength = speed.
Common traps
- Confusing mass (kg) with weight (newtons); weight = mg.
- Mixing up series and parallel rules for resistance.
- Treating speed and velocity as interchangeable when direction matters.
- Using degrees instead of kelvin in gas-law questions.
- Forgetting that in a vacuum all objects fall with the same acceleration.
Worked example
Two resistors, 6 Ω and 3 Ω, are connected in parallel across a 12 V battery. Total resistance? 1/R = 1/6 + 1/3 = 1/6 + 2/6 = 3/6, so R = 2 Ω. Current from the battery: I = V/R = 12/2 = 6 A. Rule of thumb: a parallel combination is always smaller than the smallest individual resistor - a quick sanity check that catches most errors.