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SSC JE ME Previous Paper 9 (Held on: 28 October 2020 Evening)

Option 1 : Buoyancy force

ISRO Scientist Civil 2020 Paper

1777

80 Questions
240 Marks
90 Mins

__ Explanation__:

**Buoyant Force**:

- When a solid body is either wholly or partially immersed in a fluid, the hydrostatic lift due to the
**net vertical component of the hydrostatic pressure forces**experienced by the body is called the**buoyant force**. - The buoyant force on a submerged or floating body is equal to the weight of the liquid displaced by the body and acts vertically upward through the centroid of a displaced volume known as the centre of buoyancy.

__Additional Information__

Archimedes Principle:

- Archimede's principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid.

Newton’s law of gravitation:

According to this law- When two objects having some masses are placed at a certain distance then the gravitational force is directly proportional to the product of masses and it is inversely proportional to the square of the distance between them.

\(Gravitational\;Force = F \propto \frac{{{m_1}{m_2}}}{{{r^2}}} \Rightarrow F = G\frac{{{m_1}{m_2}}}{{{r^2}}}\)

Where G is gravitational constant, r is the distance between two masses, m1 and m2 are the masses.

**Viscous Force**:

- Viscosity is the property of the liquid due to which it opposes the relative motion between the layers of the liquid.
- Viscous force is the resistive force that is acting between the layers of liquid and opposes the relative motion between the layers and is given by

\(\Rightarrow F = μ A \frac{dV}{dx}\)

Where μ = dynamic viscosity, A = area, and \(\frac{dV}{dx} = velocity \ gradient \)