Physics definition

• A physical quantity consist of a numerical magnitude and a unit
• The period of a simple pendulum is the time taken one complete oscillation
• the gradient of displacement-time graph of an object gives the velocity of the object
• The area under velocity-time graph gives the displacement of the object
• mass is the measure of the amount of matter in a body
• Weight is the gravitational force acting on an object that has mass
• A gravitational field is a region in which a mass experiences a force due to gravitational attraction
• A gravitational field strength is defined as the gravitational force per unit mass placed at that point/ field
• The inertia of an object is the reluctance of the object to change its state of rest or constant motion, due to mass
• Newton’s first law of motion states that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it
• Newton’s second law of motion stated that when a resultant force acts on an object of a constant mass, the object will accelerate in the direction of resultant force
• Newton’s third law of motion states that if bodybA exerts a force F12 on body B, then body B will exert an equal and opposite force F21 on Body A
• The moment of a force about a pivot is the product of the force f and perpendicular distance d from the line of action of force
• The principle of moment states that when a body is in equilibrium, the sum of clockwise moments about a pivot is equal to the sum of anticlockwise moment about the same pivot
• The centre of gravity of an object is an imaginary point where the entire weight of the object seems to act
• The stability of an object is a measure of its ability to return to its original state
• the principle of conservation of energy states that energy cannot be created or destroyed. energy can be transferred from one store to another. the total energy of an isolated system is constant. ch7
• work done by a constant force of an object is the product of the force and the distance moved by the object in the direction of the force. ch7
• power is defined as the work done or energy transferred per unit time. ch7
• The kinetic particle model of matter is made up of tiny particles that are in continuos motion ch8
• temperature rises with the average kinetic energy of the particles in a body and vice versa ch8
• At the particle level, pressure is the average force exerted by the particles per unit area. Ch8
• thermal equilibrium describes a state in which two or more objects have the same temperature and that there is no net transfer of energy between them. ch9
• conduction is process of energy transfer where the energy is transferred through the passing on of vibrational movement from one particle to anot her. ch9
• convection is a process of energy transfer by the means of convection current in a fluid, due to difference in density ch9
• radiation is the process of energy transfer by electromagnetic waves. it does not require a medium. ch9
• internal energy is an energy store made up of the total kinetic energy associated with random motion and the total potential energy between the particles in the system ch10
• Heat capacity of an object is the change of its internal energy per unit change in temperature ch10
• specific heat capacity of an object is the change of its internal energy per unit mass per unit change in its temperature
• Latent heat is the energy released or absorbed to change the state of a substance, at a constant temperature ( joule)
• Latent heat of fusion is the amount of energy transferred to change a substance between the solid and liquid states, at a constant temperature (joule)
• Specific latent heat of fusion is the amount of energy transferred per unit mass of a substance to change between the solid and liquids states, at a constant temperature. (Joule)
• Latent heat of vaporisation is the amount of energy transferred to change a substance between the liquid and gaseous state, at a constant temperature
• Specific latent heat vaporisation is the amount of energy transferred per unit mass of a substance to change it between the liquid and gaseous states, at a constant temperature
• a wave is a disturbance that propagates through space, transferring energy with it but not matter