1. a 40-kg woman in an elevator is accelerating upward at a rate of 2.0 m/s2. 2. an upward force of 35 n is applied via a string to lift a ball with a mass of 2.3 kg. (a) what is the net force acting upon the ball? magnitude 3.at a given instant in time, a 14-kg rock that has been dropped from a high cliff experiences a force of air resistance of 30 n. what are the magnitude and direction of the acceleration of the rock?