(a) What is the acceleration of two falling sky divers (mass 102.0 kg including parachute) when the upward force of air resistance is equal to one-fourth of their weight? ________ m/s2 (downward) (b) After popping open the parachute, the divers descend leisurely to the ground at constant speed. What now is the force of air resistance on the sky divers and their parachute? See Fig. 4-34. _____ N (upward) i need help on starting this problem...like what equation(s) would i use?? thanks so much!