100+ Physics Hydrostatics Questions and Answers - 1

Question: 1

What is the use of a barometer?

A barometer is used to measure the atmospheric pressure. An Italian scientist Torricelli designed it.

Question: 2

State the principle of hydrometer?

When a body floats in any liquid, the weight of the floating body is equal to the weight of the liquid displaced.

A hydrometer is based on this principle.

It is used to find the specific gravity of a liquid and hence its density.

Question: 3

What are plimsoll lines?

To indicate the depth upto which the ship can sink in seawater of different densities at different climatic conditions, several lines are marked on the sides of the ship to ensure the stability and safety of the ship. These lines are called Plimsoll lines, named after the historical sailor captain, Plimsoll.

The ship should not be loaded too much. Its load depends upon the density of sea water in which it travels, if the load exceeds the limit, the ship would sink.

Question: 4

State the laws of floatation?

The laws of floatation are

1. The weight of the floating body is equal to the weight of the liquid displaced.

2. The centre of gravity of the floating body and the centre of gravity of the displaced liquid (centre of buoyancy) lie in the same vertical line.

Question: 5

Define pressure?

Pressure is defined as the thrust that acts normally on unit area.

The unit of pressure is Nm^-2.

Pressure = Thrust/area.