11) a 0.2 kg apple on an apple tree has a potential energy of 10 j. it falls to
the ground, converting all of its pe to kinetic energy. what is the velocity
of the apple just before it hits the ground?
now choose from one of the following options why?
om/s
2 m/s
10 m/s
50 m/s

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".