Fluid Mechanics | MCQs

Explanation

Answer:

B

According to Archimedes' principle, when an object is completely or partially submerged in water, the water moves according to its volume. The body swims in the water when its weight is lighter than the weight of the same amount of water. If its weight is equal to the weight of the same amount of water, it remains floating.

Explanation

A piece of steel sinks in water because steel is denser than water. However, a steel ship is a hollow object made of steel and contains a lot of air in it.

Due to presence of a lot of air in it, the average density of the ship becomes less than the density of water. Hence a ship floats in water.

Explanation

To find the minimum external force needed to crack the windows, we can use the formula:

Force (F) = Pressure (P) × Area (A)

Given:

P = 660 kPa = 660,000 Pa (converting kPa to Pa)

Diameter (d) = 0.30 m

Radius (r) = d/2 = 0.15 m

Area (A) = πr² = π(0.15)² ≈ 0.0707 m²

Now, calculate the force:

F = P × A ≈ 660,000 Pa × 0.0707 m² ≈ 46,662 N ≈ 47,000 N

Explanation

Explanation

Explanation

Answer:

A

The proportion in the sea is decreasing. Seawater is denser than river water, so ships suffer more damage.

Explanation

Explanation

Explanation

Surface tension acts like a stretched membrane on the water's surface, and the surface tension along the blade's edges is greater than the blade's weight.

The force of surface tension acts tangentially to the liquid surface on the circumference of the blade.

Explanation

A Ship/boat floats based on the Archimedes Principle.

Archimedes principle:

the principle of Archimedes states "When a body is immersed in a liquid, an upward thrust, equal to the weight of the liquid displaced, acts on it."

Thus, when a solid is fully immersed in a liquid, it loses weight which is equal to the weight of the liquid it displaces.