engineering notes

 Work w ork is said to be done by a force if body is displaced due to application of force on it. Mathematically, it is measured by the product of force along the direction of displacement and displacement. If ፀ be the angle between the direction of force and displacement, then the component of the force along the direction of displacement is Fcosፀ . ∵ W= (Fcosፀ)S

Velocity  The rate of change of displacement is called velocity. It is a vector quantity and its SI unit is m/s. Average velocity: The ratio of total displacement of a body to the total time taken is called average velocity.

  Newton's Laws of motion Newton's first law of  motion: It states that ,"everybody in this universe continues its state of rest or of uniform motion in a straight line unless an external force is acted upon it. According to this law a body cannot change its state by itself. The property of a body due to which it cannot change its state by itself is called inertia. So Newton's first law of motion is also called law of inertia. From first  law of motion, a body cannot change its state by itself. some external agency is required to change the state of a body. The external agency which changes the state of a body is called force. Thus, Newton's first law gives definition of force. Mathematically, Newton's first law of motion can be expressed as  For F=0  ,    v= constant. Linear momentum The product of mass and velocity of a body is called its momentum. It is a vector quantity and denoted by p i.e  P= mv Its SI unit is kgm/s

 

 

 

 Prism is a transparent medium bounded by two triangular surfaces and three rectangular surfaces.

 The phenomenon of bending of light at interface when it move from one medium to another medium is known as refraction of light.

 

 Lens is a transparent medium bounded by two spherical surfaces. There are different types of lens such as convex lens , concave lens, plano-convex lens etc.

 The phenomenon of splitting of white light into its constituent seven colors is known as dispersion of light.

  Reversible Reaction Those reaction in which product form reactant is known as reversible reaction.

  Thermodynamic system It is an assembly or collection of large number of particles(atoms, ions or molecules) at certain temperature, pressure and volume. If a thermodynamic system can exchange heat with the surrounding then the system is called closed system. It a thermodynamic system cannot exchange heat with the surrounding then it is called isolated system.