In part a of the figure, particles 1 and 2 move around point O in circles with radii 2 m and 4 m. In part b, particles 3 and 4 travel along straight lines at perpendicular distances of 4 m and 2 m from point O. Particle 5 moves directly away from O. All five particle s have the same mass and the same constant speed. (a) Rank the particles according to the magni�tudes of their angular momentum about point O, greatest first. (b) Which particles have negative angular momentum about point O?