Question

Прошу помогите физика 1.чему равна архимедова сила, действующая на кусок мрамора объемом 40см³, наполовину погруженный в воду?2.какая требуется сила, чтобы удержать под волой пробковый пояс массой 2 кг, объём которого 10дм³?​

Answer 1

Ответ:

1. 0.02 H или 20 мН

2. F ≥ 80 H

Объяснение:

1.

V = 40 см³ = 40·10⁻⁶ м³

ρ = 1000 кг/м³ - плотность воды

g = 10 Н/кг

----------------------------------

Архимедова сила

Fа = 0.5ρgV = 0.5 · 1000 · 40·10⁻⁶ = 0.02 (H) = 20 мН

2.

m = 2 кг

V = 10 дм³ = 0,01 м³

ρ = 1000 кг/м³ - плотность воды

g = 10 Н/кг

--------------------------------------------

Для удержания пояса под водой силой F необходимо, чтобы

F + mg ≥ Fа

Архимедова сила

Fа  = ρgV

тогда

F ≥  ρgV - mg

F ≥  10 · (1000 · 0.01 - 2)

F ≥ 80 (H)

Answer 2

Archimedes' Principle and Buoyant Force

1. The Archimedes' principle states that an object submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by the object. The buoyant force can be calculated using the formula:

Buoyant force = weight of the fluid displaced

In this case, we have a marble with a volume of 40 cm³, half of which is submerged in water. To calculate the buoyant force, we need to determine the weight of the water displaced by the marble.

The density of water is approximately 1 g/cm³ or 1000 kg/m³. Since half of the marble is submerged, the volume of water displaced is 20 cm³.

Therefore, the weight of the water displaced is:

Weight = density × volume = 1000 kg/m³ × 20 cm³ ÷ 1000000 cm³/m³ = 0.02 kg

Thus, the Archimedes' force acting on the marble is equal to the weight of the water displaced, which is 0.02 kg.

Therefore, the Archimedes' force acting on the marble is 0.02 kg. [[1]]

Holding a Cork Belt under Water

2. To calculate the force required to hold a cork belt under water, we need to consider the buoyant force acting on the cork belt.

The buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. In this case, the cork belt has a mass of 2 kg and a volume of 10 dm³.

The density of cork is typically around 240 kg/m³. Therefore, the volume of the cork belt in cubic meters is:

Volume = 10 dm³ ÷ 1000 = 0.01 m³

The weight of the water displaced by the cork belt is:

Weight = density × volume = 240 kg/m³ × 0.01 m³ = 2.4 kg

Thus, the buoyant force acting on the cork belt is 2.4 kg.

To hold the cork belt under water, an equal and opposite force must be applied. Therefore, the force required to hold the cork belt under water is also 2.4 kg.

Therefore, the force required to hold the cork belt under water is 2.4 kg. [[2]]