# Elasticity, Pressure, Gravitational Force

## Elasticity, Pressure, Gravitational Force

#### ELASTICITY

Ability of a body to return to its original shape is called
Ans: Elasticity
Hierarchy of elasticity
Ans: Steel > Rubber

#### PRESSURE

The force per unit area is called
Ans: Pressure
Pressure = Force/Area
The SI Unit of pressure = Pascal or N/m2
Unit of thrust
Ans : Newton
CGS unit
Ans : dyne /cm2
Force acts more on objects having
Ans : Low Surface area

#### ATMOSPHERIC PRESSURE

Atmospheric pressure = 760mm of Mercury
Unit of Atmospheric pressure
Ans : Bar
1 bar = 10^5 pascal
Pressure at sea level is taken as the
Ans : Standard Atmospheric Pressure
Barometer is used to calculate
Ans : Atmospheric Pressure
The liquid used in Barometer
Ans : Mercury

#### BAROMETER

Liquid Level change Indication
Rising-Calm climate
Sudden fall-Storm

#### GRAVITATIONAL FORCE

The mutual attractive force between two point masses m1 and m2, is inversely propotional to the square of the distance between them
Ans : Newton's law of Gravitation
Fa^m1m2/d2 ->F=G^m1m2/d2
g -> gravitational constant
Force of attraction between any two bodies in the universe is called
Ans : Gravitation
Law of gravitation was discovered by
Ans : Sir Isaac Newton
Weakest force in nature
Ans : Gravitational Force
The force keeps the earth and other planetary objects in their orbits around the sun
Ans : Gravitational Force
The acceleration with which the freely falling bodies are attracted towards the earth is called the
Ans : Acceleration due to gravity (g) g = 9.8m/s2 (32.2 feet/s2)
Weight of freely falling body
Ans : Zero

#### VALUE OF'G' IS

Maximum at Polar regtons
Minimum at Equatorial regions
Zero at the center of the earth
Universal Law of Gravitation was put forward by
Ans : Sir Isaac Newton
The 'g' is maximum on Jupiter and minimum on the planet
Ans : Mercury
Astronaut cannot drink lemonade with the help of a straw because
Ans : There is no atmosphere on the moon