Physics Stpm Sem 1 Definition

ve locity Acceleration, a = rate of change of velocity Newton’s first law: A body will either remain at re st or continue move at constant velocity provided there is no external force acted on it. Newton’s second law: The rate of change of momentum of the body is directly proportional to the resultant force acting and it occurs in the direction of the force. Newton’s third law: For every action, there is an equal but opposite reaction and the two forces act on different bodies.

Principle of conservation of momentum: The total linear momentum of a closed system is always constant. Centre of mass  is a single point on which the whole mass o f a body is assumed to concentrate. Degree of freedom of a gas molecule: The number of independent ways in which a molecule can acquires energy. Law of equipartition of energy: The total kinetic energy of a gas molecule is divided / distributed equally among its effective number of degrees of freedom and the energy acquired by each degree of freedom is ½ kt. Internal energy is the sum of kinetic energies and potential energies for all the gas molecules in the gas system. Specific heat capacity, c: The amount of heat needed to increase the temperature of 1kg of the substance by 1 kelvin or 1 degree celcius. Heat capacity, C: The amount of heat needed to increase the temperature of the body by 1 kelvin. Molar heat capacity, Cm: The amount of heat needed to increase the temperature of 1 mol of gas by 1 ke lvin. Molar heat capacity at constant volume, Cvm: The amount of heat needed to increase the temperature of 1 mol of gas by 1 kelvin at constant volume. Molar heat capacity at constant pressure, Cpm: The amount of heat needed to increase the temperature of the gas by 1 kelvin at constant pressure. First law of thermodynamic: thermodynamic: The heat supply to a gas system is equal to the sum of the increase in internal energy of the gas and the work done by the gas.

Isothermal change: It is a change to a gas system occurring at constant temperature. Adiabatic change: It is a change to a gas system occurring without heat entering or leaving the gas system. Thermal conductivity  is the rate of heat flow per unit cross-sectional area per unit temperature gradient. Principle of conservation of energy: The total energy of a closed system is always constant. Centripetal force: The resultant force needed to keep a body move In a circular path and it is directed towards the center of the circular path. Newton’s law of gravitational: gravitational: The magnitude of gravitational attractive force betwee n two particles is directly proportional to the product of their masses and inversely proportional to the square of their distance apart.

Gravitational field strength: The gravitational field strength at a point in a gravitational field is defined as gravitational force per unit mass acting on a body placed at a point. A synchronous satellite  is a satellite which remains stationary relative to a stationary observer from earth. Gravitational potential: Gravitational potential at a point in a gravitational field is defined as work done in bringing a unit mass from infinity to the point. Gravitational potential energy, u: The gravitational potential energy of a body at a point in the gravitational field is defined as a work done in bringing a body from infinity to a point. Escape velocity is the minimum projected velocity for a body to escape into infinity from the surface of a planet. The centre of gravity  of a body is defined as a single point where the whole weight of the body acts. Hooke’s law: The extension of a material is directly proportional to the force applied provided the proportional limit of the material is not exceeded.

stret ching of a material. Elastic potential energy / strain energy  is the work done of stretching