Problem

Two persons A and B weighing 140 and 180 lb, respectively, jump off a floating platform (i...

Two persons A and B weighing 140 and 180 lb, respectively, jump off a floating platform (in the same direction) with a velocity relative to the platform that is completely horizontal and with magnitude υ0 = 6 ft/s for both A and B. The floating platform weighs 800 lb. Assume that A, B, and the platform are initially at rest.

Neglecting the water resistance to the horizontal motion of the platform, and knowing that B jumps first, determine the speed of the platform after both A and B have jumped.