Answer:
Velocity, quantity that designates how fast and in what direction a point is moving.
Explanation:
Maybe the water wasnt stable enough and probably couldnt read the water level correctly
I’m pretty sure the answer is c and d hope this helps and good luck


Compounds contain two or more different elements.
Water is a molecule because it contains molecular bonds . Water is also a compound because it is made from more than one kind of element. (oxygen and hydrogen).
So If you like, you can say that water is a molecular compound.
HOPE IT HELPED YOU.
I would think that you would have to do 42/2=21Hz, but I'm not sure...