一、科别浮力二、临床症状三．游泳时，从沙水区涉水向深水区前进时碰到浮力越来越大，所以浮力大小与深度有关2．如图1示，气球下系一铁块，把它们一起没人水面下，然后松手使其下沉，在它们下沉的过程中所受浮力不变；3一个体积为0．05米’的救生回，皿98牛，这个救生围无法? First, the department of buoyancy II, clinical symptoms III. During the swimming, the buoyancy is getting bigger and bigger when wading from the sandy water area to the deep water area, so the buoyancy is related to the depth. As shown in Figure 1, under the balloon, a piece of iron is placed under the balloon, and they are no one under the water surface. Then they let go and let them sink. Their buoyancy is unchanged during their sinking. 3 A volume of 0.05 meters. Rescue life, dish 98 cattle, this lifesaving can not?