Physics Notes PDF

The force which a surface exerts on an NORMAL FORCE object with which it is in contact, and which is perpendicular to the surface. The force that opposes the motion of an FRICTI...

The force which a surface exerts on an NORMAL FORCE object with which it is in contact, and which is perpendicular to the surface. The force that opposes the motion of an FRICTIONAL FORCE object and which acts parallel to the surface. The force that opposes the motion of a KINETIC FRICTIONAL FORCE moving object relative to a surface. The force that opposes the tendency of STATIC FRICTIONAL FORCE motion of a stationary object relative to a surface. A body will remain in its state of rest or NEWTON’S FIRST LAW OF MOTION motion at constant velocity unless a non- zero resultant/net force acts on it. When a net force acts on an object, the object will accelerate in the direction of NEWTON’S SECOND LAW OF MOTION the force and the acceleration is directly proportional to the force and inversely proportional to the mass of the object. When object A exerts a force on object B, NEWTON’S THIRD LAW OF MOTION object B SIMULTANEOUSLY exerts an oppositely directed force of equal magnitude on object A. The gravitational force the earth exerts on WEIGHT any object on or near its surface. NEWTON’S LAW OF UNIVERSAL Each body in the universe attracts every GRAVITATION other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres  MOMENTUM The product of an object’s mass and its velocity. NEWTON’S SECOND LAW OF MOTION IN The net force acting on an object is equal TERMS OF MOMENTUM to the rate of change of momentum of the object in the direction of the net force. IMPULSE The product of the net force acting on an object and the time the net force acts on the object. ISOLYTED SYSTEM AS USED IN PHYISCS A system on which the net external force is zero. PRINCIPLE OF CONSERVATION OF The total linear momentum of an isolated LINEAR MOMENTUM system remains constant (is conserved). PROJECTILE An object which has been given an initial velocity and then it moves under the influence of the gravitational force only. FREE FALL The motion during which the only force acting on an object is the gravitational force. WORK ENERGY THEOREM The NET work done on an object is equal to the change in the kinetic energy of the object. CONSERVATIVE FORCE A force for which the work done in moving an object between two points is independent of the path taken. NON-CONSERVATIVE FORCE A force for which for which the work done in moving an object between two points depends on the path taken. PRINCIPLE OF CONSERVATION OF The total mechanical energy in an isolated MECHANICAL ENERGY system remains constant. POWER The rate at which work is done or energy is expended. DOPPLER EFFECT The change in frequence(or pitch) of the sound detected by a listener, because the sound source and the listener have different velocities relative to the medium of sound propagation. COULOMB’S LAW The magnitude of the electrostatic force exerted by one point charge on another point charge is directly proportional to the product of the magnitude of the charges and inversely proportional to the square of the distance between them. ELECTRIC FIELD A region of space in which an electric charge experiences a force. ELECTRIC FIELD AT A POINT The electrostatic force experienced per unit positive charge placed at that point. OHM’S LAW The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature. Emf The maximum energy provided by a battery per unit charge passing through it. RMS POTENTIAL DIFFERENCE The AC potential difference which dissipates/produces the same amount of energy as an equivalent DC potential difference. RMS CURRENT The alternating current which dissipates/produces the same amount of energy as an equivalent direct current. PHOTOELECTRIC EFFECT The process whereby electrons are ejected from a metal surface when light of suitable frequency is incident on that surface. THRESHOLD FREQUENCY The minimum frequency of light needed to emit electrons from a certain metal surface. WORK FUNCTION The minimum energy that an electron in the metal needs to be emitted from the metal surface. ATOMIC ABSORPTION SPECTRUM A spectrum that is formed when certain frequencies of electromagnetic radiation passing through a substance is absorbed. ATOMIC EMISSION SPECTRUM A spectrum that is formed when certain frequencies of electromagnetic radiation are emitted due to an atom making a transition from a higher energy state to a lower energy state.