ScienceFreako

<div>My teacher gave us an assessment to do and I encountered some problems. Would be glad if you guys can help.</div><div><br></div><div>1. Why is it that a cup with lesser amount of water produce a lower pitch sound as compared to an identical cup with more water when hit with a stick. (And vice versa)</div><div><br></div><div>2. Sound energy is produced by vibrations of air particles right?</div>