PHYSICS · Single correct · AP · Physics 1: Algebra-based · Kinematics · Kinematics
Problem
A particle moves along the polar curve r=f(θ) with dtdθ=0. At an instant when dθdr=0, which of the following best describes the instantaneous direction of the particle’s velocity vector?
(a) It is directed radially outward from the pole.
(b) It is directed radially inward toward the pole.
(c) It is tangent to the curve and perpendicular to the radial line.
(d) The particle is momentarily at rest, so the direction is undefined.