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Assistant General Science

Physics – 02

വർക്ക്, എനർജി, പവർ എന്നീ പ്രധാന ഭാഗങ്ങളാണ് ഇന്നത്തെ പാഠത്തിൽ ഉൾപ്പെടുത്തിയിരിക്കുന്നത്.

  • Law of Conservation of Energy was put forwarded by

Albert Einstein

 

  • The law which states “Energy can neither be created nor be destroyed but can be transformed from one form to another”

     Law of Conservation of Energy

 

  • Einstein proposed special theory of Relativity in

   1905

 

  • Einstein proposed General theory of Relativity in

       1915

 

  • Equation mentioning the relation between matter and Energy

         E=mc²

 

  • A work is said to be done if

     There is displacement of body in the direction of force applied

 

  • Equation mentioning the relation between Force and Work

   W=FxD [D: Displacement]

 

  • Ability to do work is called

 Energy

 

  • CGS unit of work

Erg (1 Joule = 107Erg)

 

  • The term Energy was first coined by

Thomas Young

 

  • Mechanical Energy of an object is occurred due to

     Its motion

 

  • Two type of Mechanical Energy of an object is

   Potential Energy and Kinetic Energy

 

  • Energy possessed by a body by virtue of its position is called

   Potential Energy (PE)

 

  • Potential Energy of an object of mass ‘m’ situated at a height of ‘h’ above the ground is

mgh (g: acceleration due to gravity)

 

  • Energy stored in water reservoir of a dam, in a compressed spring etc are examples of

   Potential Energy

 

  • Potential Energy of an object at rest on ground is

       Zero

 

  • Potential Energy increases as the height

   Increases

 

  • Energy possessed by a body due its motion is called

Kinetic Energy (KE)

 

  • Energy changes in a body thrown vertically upwards

Potential Energy increases and Kinetic Energy decreases

 

  • Potential Energy of a free falling body is

 Decreasing

 

  • Kinetic Energy of an object of mass ‘m’ moving with velocity ‘v’ is

     1/2 mv²

 

  • If the velocity of an object is doubled, its Kinetic Energy becomes

Four times

 

  • If the mass of a moving object is doubled, its Kinetic Energy becomes

           Doubled

 

  • A moving stone or moving bullet possesses

 Kinetic Energy

 

  • Kinetic Energy of an object is always

     Positive

 

  • Examples of Law of conservation of momentum

           Rocket propulsion, Jet engine, Fire a pistol etc

 

  • All objects in free fall near the Earth have same

 Acceleration

 

  • The acceleration of an object in free fall is independent of its

     Mass

 

  • Highest velocity attainable by an object as it falls through air

 Terminal Velocity

 

  • An object falls through air will attain its Terminal Velocity when

       The force of resistance equal to the gravitational pull on the object

 

  • Rate of doing work is known as

   Power (P) [Work/Time]

 

  • 1 Watt =

     1 Joule/Sec

 

  • 1 Horsepower =

746 Watts


(To be Continued…)