Basic terms part #3

 

Basic terms part #3

Torque: When we applied force on an object and the applied point is other than center point the object will start rotation. So this rotation of object is called torque.

Couple: The two equal and opposite parallel forces acting on a different lines on a body is called couple.

Equilibrium: When the several forces acting on a body but there is no change in translational motion as well as rotation motion then the body said to be in equilibrium.

Stability: How hard to displace an object from its equilibrium is known as stability.

Law of universal gravitation: The force attraction between two objects is directly proportional the product of their masses and inversely proportional to the square of distance between them. Mathematically:

                                                                      F = G     

Gravitational field: The region around the earth where an object fells the force of attraction is known as  gravitational field. It is non-contact force.

Satellite: Any object naturally or man-made that orbits anther objects larger than itself by force of gravity. Satellite have two types

a)      Natural satellite: A natural body orbiting anther body and the another body is so large that the center of mass is well within the larger body is called natural satellites.

b)      Artificial satellites: Any object for any purposely placed into the orbit of earth or other planets, star or sun are termed as artificial satellites.

Orbital velocity: The velocity of a satellite which is around the another object from some specific height is known as orbital velocity.

Gravitational acceleration: The acceleration of a body due to which the body moves towards the center of the earth is called is gravitational acceleration “g”. The value of g decreases as altitude increase.

Work: When we apply force to an object and the object moves in the direction of force, we say the work is done. The unit of work is the joule.

Kinetic energy: when a body in motion this body have an energy which is called kinetic energy.

                                                                 K.E = mv²

Potential energy: When a body have some position from the center of the earth it have energy which is called potential energy.

                                                                P.E = mhg

Law of energy conservation: This law states that “energy can not be created nor to be destroyed in any process. But it can be converted from one form to another.

Mass energy equivalence: According to the Einstein “the mass and energy can be interchangeable to one another from the following equation.

                                                                E = MC²

Major sources of energy: Fossil fuels (coal, oil, natural gas), Biomass, Geothermal energy, Wind energy, Nuclear energy, solar energy, and Hydroelectric energy.

Efficiency: It is the ratio between useful output work and input work. Or the ratio between useful energy output and input energy.

                                                      Efficiency =

Power: The rate at which work is done is called power. It unit is joule per second its called watt.

Energy: The ability to do work is called energy.

Density: The mass of substance per unit volume is called density. Its S.I unit is kgm^-3.

                                                                 Ῥ=

Pressure: The force per unit area is called pressure. Its unit is pascal.

                                                              P =