Inside an elevator , a businessman is holding a large briefcase whose mass is equal to 4.0 Kg. A) compite the force exerted by the businessman to hold the briefcase while the elevator is at rest ? B) What is the force need it to hold the briefcase when the elevator accelerated upward at a rate of 1.5 m/s^2? C) What is the force needed to hold the briefcase if the elevator is in a free fall ? (I.e moving downward with acceleration equal to g )