Introduction to Classical Mechanics · Problem 13.5

General Relativity — Morin

Physics — Mechanics · acceleration-at-rest

Problem

Acceleration at rest Show that the derivative of

v \equiv \sqrt{v_x^2 + v_y^2 + v_z^2}

equals

a_x

, independent of how the various

v_i

's are changing, provided that

v_y = v_z = 0

at the moment in question.