You can tell if vector is an unit because it has something to do with taking the magnitude of the vector.
also has a length 1. thus you should use pythagoras to check.
Hope this help
I believe the answer is "radioactive decay".
Usually, Scientists use "Parallax Method" in order to determine the different positions of an object
Hope this helps!
To solve the problem, we can use Charle's law, which states that for an ideal gas at constant pressure the ratio between absolute temperature T and volume V remains constant:

For a gas transformation, this law can be rewritten as

(1)
where 1 and 2 label the initial and final conditions of the gas.
Before applying the law, we must convert the temperatures in Kelvin:


The initial volume of the gas is

, so if we re-arrange (1) we find the new volume of the gas:
I will be brief
5. There is no displacement as it didn't move
6. Time cannot go backwards so it cannot be negative