[填空题]
A tuning fork is set into vibration above a vertico )d-b8pn4h 4ly l8rsh1zmoy.al open tube filled sxd -d580wwo-)vlp jk with water (Fig. 12–35). The water level is allowed to drop slowly. As it does so, the air in the tube above the water level is heard to resonate with the tuning fork when the distance from the tube opening to the water level is 0.125 m and again at )pjw-8v50o k-x dswld 0.395 m. What is the frequency of the tuning fork? Hz
