An elevator accelerates upward at 1.2 m/s 2 . The acceleration of gravity is 9.8 m/s 2 . What is the upward force exerted by the floor of the elevator on a(n) 51 kg passenger? Answer in units of N. 003 (part 2 of 2) 10.0 points If the same elevator accelerates downwards with an acceleration of 1.2 m/s 2 , what is the upward force exerted by the elevator floor on

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".