Answer:
The frequency of the piano string is <em>1059 Hz</em>.
Explanation:
The frequency beat (fb), 2 beats/second, is the absolute difference between the frequency of the tuning fork (1056 Hz) and the frequency of the piano string.
As the piano string gets tightened, the frequency beat becomes 3 beats/second.
Therefore,
fb = 
Yes, in a classical model of the singly-ionized helium atom, a single electron orbits the nucleus.
<h3>What is singly ionized helium?</h3>
Singly ionized helium is an atom that has lost one electrons from its outermost shell. We consider its remaining electron like a hydrogen electron. There is only one difference between a hydrogen atom and a singly ionized helium atom which is the number of protons in the nucleus so the nucleus charge on singly ionized helium is -1.
Learn more about helium here: brainly.com/question/26226232
Given that they are all on the same bus that is travelling in a straight line at the same velocity, when Elle throws the ball directly upwards, the ball will simply fall back to her. This is because the bus, Elle, and the ball are all travelling in the same direction and at the same speed. Among the choices, the correct answer is A.