Apples of diameter 12cm are picked from a tree and cooled in a stream of cold water to reduce their metabolism so that they store longer. Consider a stream of water at 5°C and a velocity of 0.04 m/s flowing over an individual apple. If each cooling tank contains 1000 apples, and assuming the apple has an initial temperature of 25°C, how much energy (W) do you need to supply the tank to keep it cool (based on the amount of thermal energy being removed from each apple according to the initial conditions)?

The frequency of a tuning fork can be found by the method shown. a long tube open at both ends is submerged in a beaker of water, and the vibrating tuning fork is placed near the top of the tube. the length l of the air column is adjusted by moving the tube vertically. the sound waves generated by the fork are reinforced when the length of the air column corresponds to one of the resonant frequencies of the tube. the smallest value for l for which a peak occurs in sound intensity is 7 cm. l what is the frequency of the tuning fork? the speed of sound in air is 345 m/s. answer in units of hz