When you blow across the top of a soda bottle, it acts like a closed
pipe. If it creates a fundamental
frequency of 680 Hz, how deep
is the bottle?
(Speed of sound = 343 m/s)
(Unit = m)
Please need help

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?