When a copper ball with a weight of 4.5n and a volume of 0.5dm3 is immersed in water and let go, the buoyancy of the copper ball when it is still is zero______ N．

When a copper ball with a weight of 4.5n and a volume of 0.5dm3 is immersed in water and let go, the buoyancy of the copper ball when it is still is zero______ N．

The buoyancy of the copper ball after being completely immersed is f-floating = ρ GV row = 1000kg / m3 × 9.8n/kg × 0.5 × 10-3m3 = 4.9n ＞ 4.5n, so the copper ball will float up after being immersed in the water, and finally float on the water surface. The buoyancy is equal to its own gravity, which is 4.5n

A copper ball with a weight of 4.5 N and a volume of 0.5 cubic decimeter is immersed in water and let go?

Answer: 4.5n
Analysis: when immersed, the buoyancy of copper ball is
F floating = ρ water GV = 1000 × 10 × 0.5 × 10 ^ - 3 = 5N
5N＞4.5N
That is buoyancy > gravity, the ball will rise, and finally become floating, floating objects buoyancy is equal to self weight
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