Answer: The acceleration of the object is 0.67m/s^2 west.
Explanation: Here we are given the initial velocity and final velocity as well as the time taken. Acceleration is the change in velocity per unit time, thus the equation becomes.
a=dv/t
a=vf-vi/t
a=-2.1-4.7/3.9
a= 0.66m/s^2 west
Matter can exist in one of three main states: solid, liquid, or gas. Solid matter is composed of tightly packed particles. A solid will retain its shape; the particles are not free to move around. Liquid matter is made of more loosely packed particles. Hopefully this helps:)