Based on the information in the question, a light year is the distance traveled light in one year. Then if the light from the star Centauri takes 4.2 years to reach the earth, then its distance from earth is 4.2 light years.
Answer:
<em>Answer: positive velocity & negative acceleration</em>
Explanation:
<u>Accelerated Motion</u>
Both the velocity and acceleration are vectors because they have magnitude and direction. When the motion is restricted to one dimension, i.e. left-right or up-down, the direction is marked with the sign according to some preset reference.
The locomotive is moving at a certain speed with a (so far) unknown sign but the acceleration has a negative sign. Since the locomotive comes to a complete stop it means the velocity and the acceleration are of opposite signs.
Thus the velocity is positive.
Answer: positive velocity & negative acceleration
mass gram, time sec, temp kelvin, vol liter, dens grams/cm3
