On a nice summer day when the temperature is 23 C, you purse your lips and whistle across the top of an empty pop bottle that is 29 cm tall. What must be the frequency of your whistle to make the air in the bottle vibrate in the fourth resonant length? I​

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?