PHY102: Comprehensive Physics Notes – Mechanics,
Waves, Energy, and Nuclear Physics
weight - force a body exerts due to the pull of gravity
mass - the measure of the amount of material in a body
weight= - mass x velocity
objects are stable if - lower com
large surface area
objects will topple if - vertical line through the com falls outside the base
a moment is produced which causes the object to rotate
com is - the point where all the mass of that object may be considered to be
balance at com because - the moments on each side are equal
density is - mass per unit volume
density= - mass/volume
density tells us - how closely the particles are packed
friction is - a force that opposes motion
air resistance or drag - occurs when the object moves through air or fluid
reduce friction by - lubrication
changing the material or fluid
rollers
streamlining
friction acts in the - opposite direction of the object
friction exists - when two surfaces move over each other
a force can - change the direction of motion
change the shape of things
, start objects moving and slowing down
2 main groups - contact and distant
contact - forces touch the object and produce a change of shape or state of motion
distant - forces act at a distance
1st law - a body will remain at rest or move at a constant velocity if the resultant force acting on
the body is zero
balanced forces exist when - two forces act in opposite directions but are the same
size
2nd law - if a resultant force acts on a body the body will not remain at rest or move at constant
velocity, it will accelerate
resultant force= - mass x acceleration
principal of moments - when a object is balanced, the total sum of the clockwise moments is
equal to the sum of the anticlockwise moments, about the pivot
distance is - ground covered
displacement is - shortest distance from start to finish in a certain direction
speed is - rate of change of distance
velocity is - rate of change in displacement
acceleration is - rate of change in velocity
scalar - magnitude
vector - magnitude and direction
acceleration= - velocity/time
unit of acceleration - m/s²
moment= - force x distance
unit of moments - newton metre
unit of density - kg/m³
size of moment depends on - size of force
Waves, Energy, and Nuclear Physics
weight - force a body exerts due to the pull of gravity
mass - the measure of the amount of material in a body
weight= - mass x velocity
objects are stable if - lower com
large surface area
objects will topple if - vertical line through the com falls outside the base
a moment is produced which causes the object to rotate
com is - the point where all the mass of that object may be considered to be
balance at com because - the moments on each side are equal
density is - mass per unit volume
density= - mass/volume
density tells us - how closely the particles are packed
friction is - a force that opposes motion
air resistance or drag - occurs when the object moves through air or fluid
reduce friction by - lubrication
changing the material or fluid
rollers
streamlining
friction acts in the - opposite direction of the object
friction exists - when two surfaces move over each other
a force can - change the direction of motion
change the shape of things
, start objects moving and slowing down
2 main groups - contact and distant
contact - forces touch the object and produce a change of shape or state of motion
distant - forces act at a distance
1st law - a body will remain at rest or move at a constant velocity if the resultant force acting on
the body is zero
balanced forces exist when - two forces act in opposite directions but are the same
size
2nd law - if a resultant force acts on a body the body will not remain at rest or move at constant
velocity, it will accelerate
resultant force= - mass x acceleration
principal of moments - when a object is balanced, the total sum of the clockwise moments is
equal to the sum of the anticlockwise moments, about the pivot
distance is - ground covered
displacement is - shortest distance from start to finish in a certain direction
speed is - rate of change of distance
velocity is - rate of change in displacement
acceleration is - rate of change in velocity
scalar - magnitude
vector - magnitude and direction
acceleration= - velocity/time
unit of acceleration - m/s²
moment= - force x distance
unit of moments - newton metre
unit of density - kg/m³
size of moment depends on - size of force
