Relative Velocity Formula — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Relative Velocity Formula Classical mechanics in inertial reference frames. Define position vectors r A and r B with respect to an origin O. Define relative position r AB = r A - r B. Differentiate the relative position equation with respect to time: d(r AB)/dt = d(r A)/dt - d(r B)/dt. Substitute velocity definitions to obtain v AB = v A - v B. Velocities must be non-relativistic (v << c). Both object velocities must be measured relative to the same reference frame. Thinking relative velocity is always the difference in speeds (ignoring direction/vector nature). Confusing the order of subtraction (v A - v B vs v B - v A). Assuming relative velocity cannot be greater than the individual velocities (incorrect in head-on collisions).