physics

• what is a physical quantity?

  a quantity that can be measured, consists of a numerical magnitude and a unit
• what is one oscillation?

  one complete to and fro motion
• what is the period of a simple pendulum?

  the time taken for one complete oscillation
• what is scalar quantity?

  a physical quantity that only have magnitude
• what is vector quantity?

  a physical quantity with both magnitude and direction
• what is speed?

  the distance moved per unit time
• what is velocity?

  the rate of change of displacement
• what is acceleration?

  the rate of change of velocity
• what is uniform acceleration?

  a constant rate of change of velocity
• what is mass?

  a measure of the amount of matter in a body
• what is weight?

  the gravitational force acting on an object that has mass
• what is gravitational field?

  a region in which a mass experiences a force due to gravitational attraction
• what is gravitational field strength?

  the gravitational force per unit mass placed at that point
• what is newton's first law of motion?

  every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it
• what does inertia of an object refers to?

  the reluctance of the object to change its state of rest or motion due to mass
• what is newton's second law of motion?

  when a resultant force acts on an object of constant mass, the object will accelerate in the direction of the resultant force
• what is newton's third law of motion?

  if body A exerts a force on body B, then body B will exert an equal and opposite force on body A
• what is friction?

  the contact force that opposes or tends to oppose motion between surfaces in contact
• what is terminal velocity

  it occurs when air resistance acting on the object is equivalent to its weight, causing the object to have zero acceleration and travel at a constant speed
• what is moment of a force about a pivot?

  the product of the force F and the perpendicular distance d from the pivot to the line of action of the force
• what is principle of moments?

  when a body is in equilibrium, the sum of clockwise moments about the pivot is equivalent to the sum of anti clockwise moments about the same pivot
• what is the centre of gravity of an object?

  an imaginary point where the entire weight of the object seems to act
• what does stability mean?

  a measure of an object's ability to return to its original position
• what is the principle of conservation of energy?

  energy cannot be created or destroyed

  energy can be transferred from one store to another

  total energy of an isolated system will be constant
• what is work done?

  work done by a constant force on an object is the product of the force and the distance moved by the object in the direction of the force
• what is power?

  work done or energy transferred per unit time
• kinetic particle of matter

  made up of tiny particles that are in continuous motion
• temperature

  rises with the average kinetic energy of the particles in a body and vice versa
• pressure

  at particle level, pressure is the average force exerted by the particles per unit area
• thermal equilibrium

  a state in which two or more objects have the same temperature and that there is no net transfer of energy between them
• conduction

  a process of energy transfer where energy is transferred through the passing on of vibrational motion from one particle to another
• convection

  a process of energy transfer by means of convection currents of a fluid (liquid or gas), due to difference in density
• radiation

  a process of energy transfer by electromagnetic waves, it does no require a medium
• internal energy

  an energy store that is made up of the total kinetic energy associated with the random motion of the particles and the total potential energy between the particles in the system
• heat capacity

  heat capacity of an object is the change of its internal energy per unit change in its temperature
• specific heat capacity

  specific heat capacity of a material is its change of internal energy per unit mass for each unit change in temperature
• latent heat

  the energy released or absorbed to change the state of a substance, at constant temperature
• latent heat of fusion

  the amount of energy transferred to change a substance between solid and liquid states, at constant temperature
• specific latent heat of fusion

  the amount of energy transferred per unit mass of a substance to change between solid and liquid states, at constant temperature
• latent heat of vaporization

  the amount of energy transferred to change a substance between liquid and gaseous states, at constant temperature