Memorise the five rotational kinematic equations as a column table Write the linear equations in the left column and their exact rotational counterparts in the right — (v = u + at) ↔ (ω₂ = ω₁ + αt), (s = ut + ½at²) ↔ (θ = ω₁t + ½αt²), etc. Practise covering each column alternately until recall is automatic. The trap: writing ω₂ = ω₁ + αθ (mixing θ for t) — a substitution error that appears in 1 in 4 student mistakes.

Identify which equation to use before calculating When α is constant, list the known and unknown variables first: write down what is given (ω₁, ω₂, α, θ, t) and circle the unknown. Choose the equation that contains exactly one unknown. If time t is absent, use ω₂² = ω₁² + 2αθ. If displacement θ is absent, use ω₂ = ω₁ + αt. The trap: applying θ = ω₁t + ½αt² when ω₂ is the unknown, then solving the resulting quadratic instead of choosing the direct formula.

Convert rpm and rev to rad/s and rad before substituting ω (rad/s) = [n (rpm) × 2π] / 60. Angular displacement in one revolution = 2π rad; in N revolutions = 2πN rad. Do this conversion as the first step — before any formula — to avoid a factor-of-2π error in the final answer. NEET 2020 asked the angular velocity of a wheel rotating at 300 rpm: ω = 300 × 2π/60 = 10π rad/s ≈ 31.4 rad/s.

Handle variable-α problems using calculus analogues When α is not constant, the suvat analogues are invalid. Use ω = dθ/dt and α = dω/dt. Integrate α(t) to get ω(t), then integrate ω(t) to get θ(t). The trap: using ω₂ = ω₁ + αt with a time-varying α, which gives a systematically wrong answer even when the formula looks correct.