Which statement best defines work? (2 points) Group of answer choices Work is the time it takes to move an object once acted upon by a force. Work occurs when balanced forces act on an object and cause movement in the direction of these forces. Work occurs when a force causes motion of an object, and this motion is in the same direction of the applied force. Work is the distance over time that an object moves once acted on by a force.

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