A 15-kg block is on a ramp which is inclined at 20° above the horizontal. It is connected by a string to a 19-kg mass which hangs over the top edge of the ramp. Assuming that frictional forces may be neglected, what is the downward acceleration of the 19-kg block? 4.0 m/s2

4.5 m/s2

4.2 m/s2

3.8 m/s2

Explain what will happen if decomposers were apsent from a forest ecoysystem.

You are standing on a boat. which of the following strategies will make the boat start moving? a. pushing the mast b. throwing some cargo out of the boat c. pushing the front ofthe boat d. pushing another passenger

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