Asled is moving down a steep hill. the mass of the sled is 50 kg and the net force acting on it is 20 n. what must be
done to find the acceleration of the sled? check all that apply.
the force of gravity must be broken into its parallel and perpendicular components.
acceleration can be found by dividing the net force by mass.
acceleration can be found by multiplying the net force by mass.
the magnitude of the force components must be multiplied by gravity.
trigonometry can be used to solve for the magnitude of the force components.
net force must be found before acceleration can be found.

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".