Explanation:
Given that,
2 strings both vibrate at exactly 220 Hz. The frequency of sound wave depends on the tension in the strings.
The tension in one of them is then decreased sightly, then
will decrese.
Beat frequency, 

So, the new frequency of the string is 217 Hz. Hence, this is the required solution.
Answer:
DMs are not accessible anymore. I assume Zuka is a staff member? the only way to talk to a staff member anymore is to report something, but even then, the probably won't even look at what they're deleting :/
May I have brainliest please? :)
A) experiment. Is the answer.
hypothesis is the educated guess about what the result of the experiment is before conducting the experiment.
Observation is what you see and record during the experiment.