Answer:
Period is 1.57 seconds
Explanation:
From simple harmonic motion :

T = 2π√(2.5÷10)
T = 0.25 × 2π
T = 1.57 s
There are no such examples on the list you've provided.
Answer:
A light year is a measure of distance as opposed to a time measurement. This is because a light year is the distance light can travel in the time of a year.
Hypothesis
A scientific hypothesis must be testable and capable of being proven false.