Tom is from London. He's now in Beijing with his parents. His father and mother teach in a school. He studies in a middle school. The school is four miles from his home. He usually walks to school. He says, "It can make me healthy." Sometimes when it rains, he takes a bus. He's never late, and he's always the first one to get to school. He's good at all his subjects, and often helps us with our English. We all love him very much.

认真观察下边漫画，回答问题：

用手把一重为3N的球全部压入水中，物体排开的水重为5N，此时球受到的浮力大小是____，放手后这个球将____（填“上浮”、“悬浮”或“下沉”），此时小球的密度____（选填“大于”、“小于”或“等于”）水的密度，当球静止时所受浮力为____ N。