Their Period number is common means their "Principal Quantum Numbers" are same
Hope this helps!
They are speed and direction.
Answer:
The ball is dropped at a height of 9.71 m above the top of the window.
Explanation:
<u>Given:</u>
- Height of the window=1.5 m
- Time taken by ball to cover the window height=0.15
Now using equation of motion in one dimension we have

Let u be the velocity of the ball when it reaches the top of the window
then

Now u is the final velocity of the ball with respect to the top of the building
so let t be the time taken for it to reach the top of the window with this velocity

Let h be the height above the top of the window

I believe your answer should be C. Speed.