There is a body having mass $m$ and performing SHM with amplitude '$a$'. There is a restoring force $F=-Kx$, where $x$ is the displacement. The total energy of the body depends upon which of the following?

What is the effect of humidity on sound waves when humidity increases?

A tuning fork of frequency $n$ produces $x$ beats per second when sounded with a vibrating sonometer string. What must have been the frequency of the string, when a slight increase in tension produces lesser beats per second than before?

A string of length $0.5$ m and mass $10^{-3}$ kg is tightly clamped at its ends. The tension in the string is $0.8$ N. Identical wave pulses are produced at one end at equal intervals of time $\Delta t$. What is the minimum value of $\Delta t$ which allows constructive interference between successive pulses?