physics content

define velocity

velocity is the rate of change of displacement

define acceleration

acceleration is the rate oh change of velocity

newtons first law

inertia: the greater the mass the greater the inertia

define inertia

inertia is the resistance to the change in velocity

newtons second law

rF = mxa

newtons third law

for every force exerted, there is an equal and opposite reaction

action reaction pair

the force must be of the same magnitude but in the opposite direction

force must be of the same type and on opposing bodies (act on different objects)

terminal velocity

terminal velocity is when maximum velocity is reached by an falling object. which is where air resistance is equal to the weight of an object

principle of moments

the principle of moments state that for an object to be in equilibrium, the sum of clockwise moments about the pivot is equal to the sum of anticlockwise moemnts about the same pivot

define centre of gravity

the centre of gravity of an object is the point through which a whole weight appears to act on

define pressure

pressure is the amount of force acting per unit area

define work done

work done is the product of the force and the perpendicular distance from the force to the line of action

principle of conservation of energy

energy can be neither created nor destroyed but it can be transferred from one store to another. the total amount of energy within an isolated system remains constant

what is a longitudinal wave

a wave that travels in the direction parallel to the direction of vibration

what is a transverse wave

its a wave that travels in a direction perpendicular to the direction of vibration

what does 50 hz mean

it refers to 50 complete waves produced in a second

em waves ranking

radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays

define critical angle

it is the angle of incidence in the optically denser medium that is refracted in the optically less dense medium at 90 degrees