계산 방법 Buoyant 힘 (Fb = ρVg): Archimedes' Principle

계산 buoyant 힘 with Fb = ρVg, 비교 무게 to decide float or sink, and 확인 일ed examples with a free buoyancy calculator.

What Buoyant 힘 Asks

Buoyant 힘 is the upward push a fluid exerts on an object that is submerged or floating. Archimedes’ principle says that push equals the 무게 of the fluid the object displaces.

In symbols: Fb = ρ V g. ρ is the fluid 밀도, V is the displaced volume, and g is gravity. The 힘 points up; 무게 points down.

If you already have ρ, V, and g and only need a 확인ed Fb, open the free buoyancy 힘 calculator first, then return here for float-vs-sink 확인s and unit traps.

The 공식

  • Fb = ρ V g — buoyant 힘 in newtons.
  • Displaced fluid 질량 = ρ V (kg when SI 단위 are used).
  • Object 무게 for comparison: W = mg.

    • V is the volume of fluid pushed aside. Fully submerged: V equals the object’s volume. Floating: V is only the submerged part.

    Float or Sink

    Find the maximum buoyant 힘 if the object were fully submerged: Fb,max = ρ V_object g. 비교 to 무게 W = mg.

  • If W < Fb,max, the object floats (only partly submerged at equilibrium).
  • If W > Fb,max, the object sinks.
  • If W = Fb,max, it is neutrally buoyant when fully submerged.

    • 무게 uses W = mg — refresh that with the 무게 calculator. 밀도 for ρ comes from the 밀도 calculator.

    Open the 밀도 calculator when you need ρ = m / V first.

    단위

  • ρ → kg/m³ (fresh water often 1000; seawater often ≈ 1025).
  • V → m³ (1 L = 0.001 m³; convert cm³ carefully).
  • g → m/s² (9.8 or 9.81).
  • Fb → N.

    • 풀이 예제

    예제 1: 0.020 m³ in fresh water

    ρ = 1000 kg/m³, V = 0.020 m³, g = 9.81. Fb = 196.2 N. Displaced 질량 = 20 kg.

    예제 2: same volume in seawater

    ρ = 1025 kg/m³. Fb = 201.105 N — more lift than fresh water.

    예제 3: 15 kg block, V = 0.020 m³

    W = 15 × 9.81 = 147.15 N. Fresh-water Fb,max = 196.2 N > W, so it floats.

    흔한 실수

  • Putting object 밀도 into Fb = ρ V g instead of fluid 밀도.
  • Leaving V in liters or cm³ without converting to m³.
  • Using full object volume for a floating object that is only partly submerged.
  • Comparing Fb (newtons) directly to 질량 (kilograms).

    • 확인 It on the 계산기

    부력 힘 calculator.

    밀도 calculator.

    무게 calculator.

    압력 calculator.

    학습 Fb = ρVg and 확인 every float/sink home일 number.

    문서

    • 탄성 위치 에너지 공식 (U = ½kx²): 계산기 & 예제
    • 계산 방법 전기 전력 (P = VI, I²R, V²/R)
    • 계산 방법 파동 속도 (v = fλ): 주파수 × 파장
    • 계산 방법 무게 (W = mg): 질량 vs 힘
    • 계산 방법 밀도 (ρ = m/V): 질량 ÷ Volume
    • 계산 방법 가속도 (a = (v − u)/t)

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