Physics 9

താപവ്യതിയാനങ്ങൾ, ചലനം, പ്രവേഗം, ത്വരണം, ചലന നിയമങ്ങൾ എന്നിവയുമായി ബന്ധപ്പെട്ട ചോദ്യങ്ങളാണ് ഇന്നത്തെ പാഠത്തിൽ

• The process of conversion of a liquid into vapour is known as

                  Evaporation

• The process of conversion of a solid directly into vapour is known as

                  Sublimation

• Example of an object showing sublimation

                  Camphor

• Quantity of heat required to convert unit mass of solid at its melting point into liquid is called

                  Latent heat of Fusion

• For ice at 0°C, the latent heat of fusion is 

                  80K Cal/kg

• Quantity of heat required to convert unit mass of liquid at its boiling point into vapour is called

                  Latent heat of vapourisation

• For water at 100°C, the latent heat of vaporisation is 

                  540K Cal/kg

• Device which converts heat energy into mechanical energy

                  Heat engine

• A body is said to be a perfectly blackbody if its

                  Absorption power is 1

• A surface which absorbs all the heat radiations incident on it is known as 

                  Perfectly black body

• Device used to measure the temperature of sun

                  Pyroheliometer

• Radiations received from a black body is called 

                  Black body radiation

• Estimated value of surface temperature of sun is

                  5778K

• Study of high temperature is known as

                  Pyrology

• Study of motion is known as

                  Mechanics

• Study of causes and changes in motion is known as

                  Dynamics

• Change in position of an object with respect to time and its surroundings is called

                  Motion

• If an object does not change its position with respect to its surroundings, it is said to be

                  Stationary

• The distance travelled by a body in unit time is called 

                  Speed (Distance/Time)

• Change in position of an object in a particular direction is called

                  Displacement

• The distance travelled by a body in a definite direction in unit time is called 

                  Velocity (Displacement/Time)

• The rate of change of velocity of a moving body is called 

                  Acceleration (Change in velocity/Time)

• Slope of velocity time graph gives

                  Acceleration

• Shape of acceleration versus mass graph for constant force is 

                  Hyperbola

• At terminal velocity the acceleration of body is

                  Zero

• If the velocity of moving body decreases, the change in velocity is called

                  Retardation or Deceleration

• Example of one dimentional motion

                  Throwing a stone straight up

• Example of two dimentional motion

                  Projectile motion, Boat in a lake, Satellite revolving uniformly around earth

• Example of three dimentional motion

                  Motion of a charged particle, A kite in air

• If a body is moving in a circular path then the motion is said to be in

                  Circular motion

• To and fro motion of an object is called

                  Oscillatory motion

• Example of oscillatory motion

                  Pendulam of a clock

• If a body is moving in a line then the motion is said to be in

                  Translational motion or Linear motion

• Translational motion in a straight line is called

                  Rectilinear motion (Eg: Lift motion)

• Translational motion in a curved path is called

                  Curvilinear motion (Eg: Motion of rocket in space)

• Motion which repeat after regular intervals of time

                  Periodic motion (Eg: Rotation of earth around sun)

• If the axis of the rotating body is within the body, its motion is said to be 

                  Spin motion or Rotational motion (Earth spin)

• When an object travels around another object, its motion is known as

                  Revolution (Eg: Earth travels around Sun)

• Motion of an object in a vertical plane under the influence of gravitational force is known as

                  Projectile motion

• Projectile path is known as 

                  Trajectory

• Projectile path is always

                  Parabola

• Projectile reach its maximum range when the angle of projection is at

                  45°

• Tendency of a body to continue its state of rest or uniform motion along a straight line is called

                  Inertia

• Law of inertia was discovered by

                  Galileo

• As the bus starts moving, a man sitting inside leans backward because of

                  Inertia of rest

• As the bus stops moving, a man sitting inside bend in forward direction because of

                  Inertia of motion

• Rotating wheel throw out mud tangentialy outward because of

                  Inertia of direction

• Force required to stop a moving body depends on

                  Its mass and velocity

• Uniform acceleration produced in a freely falling body due to gravitational pull of the earth is known as 

                  Acceleration due to gravity (g=9.8 m/s²)

• In earth acceleration due to gravity is maximum at

                  Polar regions

• In earth acceleration due to gravity is minimum at

                  Equatorial regions

• In earth acceleration due to gravity is zero at

                  Centre of the Earth
                                                                            (To be Continued...)