You are tuning a guitar by comparing the sound of the string with that of a standard tuning fork. you notice a beat frequency of 5 hz when both sounds are present. youfrequencyof5.youtighten the guitar string and the beat frequency rises steadily to 8 hz. to tune the string exactly to the tuning fork you shouldfork, youshould

When you tighten the string, the tension of the string increases, and this causes that the string vibrates faster (this is way the frequency increases) now, the beat frequency (or difference in the frequencies) starts at 5hz, then when you tighten the string it increases to 8hz, then you need to untighten the string in order to reach a beat frequency near to zero.

3 m/s²

Explanation:

Sum of forces in the x direction:

∑F = ma

68 N − 23 N = (15 kg) a

a = 3 m/s²