Explanation:
the state or quality of being efficient or able to accomplish something
Answer:
I don't know.
Explanation:
I have no idea what you are referring to.
Answer: 14.122 units
Explanation:
We have the following vector:

If we want to find its magnitude we have to use the following formula:
This is the magnitude of vector 
Answer:
T' = 0.9677T
Explanation:
The period of a pendulum is given by the following formula:

l: length of the pendulum
g: gravitational acceleration
If the length of the pendulum is decreased in 6.35% the length of the pendulum becomes:

The new period for a length of l' is:

hence, the new period is 0.9677T