define motion
the continuous change in the postition of an object in relation to another object which is regarded to be at rest
define mechanics
a branch of physics which studies the motion of objects
define scalar quantities
a quantity accurately described by a number, with approprtiate units, that has only magnitude
define vector quantities
quantities fully described with direction and magnitude
examples of scalar quantities
age, time, area, work, distance, speed and mass
examples of vector quantities
force, displacement, velocity and acceleration
define distance
a scalar quantity that refers to how much ground an object has covered during it's motion. it has magnitude but no direction.
define displacement
a vector quantity which refers to how far out of place an object is in consideration of the straight line distance covered and the position of the object from its' original position. has both direction and magnitude.
what is the formula for distance (m)
average soeed (m/s) x time (s)
what is the formula for average speed (m/s)
distance (m) / time (s)
what is the formula for time
distance (m)/ average speed (m/s)
how do you convert m/s to km/h
multiply by 3.6
how do you convert km/h to m/s
divide by 3.6
how do you write graphical displacement
distance - first direction - angle - second direction
how do you find displacement distance using trigonometry
use pythagoras (a2 + b2 = c2)
how do you find the angle of displacement using trigonometry
use sine, cosine or tangent rules to find the angle. e.g tan θ = opposite/ adjacent, and then plug in values to find θ and then plug in values to find θ
what is a bearing
an angle to an object clockwise from north
how do you write a bearing
with 3 figures e.g 90* = 090* or 230* = 230*
how do you measure a bearing
with a protractor
what is velocity
the displacement of an object per a unit of given time. It is a vector quantity, having both direction and magnitude.
formula for velocity
v = s/t
formula for displacement
s=txv
formula for time
t=s/v
what do the letters represent in the velocity formula
v = velocity, t = time, s = displacement
hwo do you write velocity
speed, unit, direction
what does a motion graph show
the motion of an object (distance and time)
on a motion graph what does each axis represent
y - axis = distance and x - axis = time
what does a flat line on a motion graph mean
no movement
what does a steeper gradient on a motion graph mean
higher speed
what does a slowly increasing curve mean on a maotion graph
gradual accelaration
what does it mean when the line on a motion graph goes down
the object travels closer towards it's starting position
what does a straight line on a motion graph mean
steady speed
how do you read speed on a motion graph
distance/time
how to go from km/h to km/min
divide by 60
how to go from km.min to km/s
divide by 60
how to go from m/s to m/min
multiply by 60
how to go from m/min to m/h
multiply by 60
m/s to cm/s
multiply by 100
m/s to km/s
divide by 1000