Q. A student throws a water balloon vertically down from the top of a building. The balloon leaves the thrower's hand with the speed of 16 m/s. How fast is it traveling after 2.6 seconds?
Q. The smallest insects that a bat can detect are around the size of one wavelength of the sound the bat makes. What is the minimum frequency of sound waves essential for the bat to detect an insect that is 0.57cm long? Suppose the speed of sound is 340m/s.