some quantities are
vectors and include size
as well as direction
speed=distance/time
distance time graphs
a small steady incline
means something is
accelerating
a steep line upwards
means it something is
travelling at speed
a horizontal line means
something is stationary
velocity and acceleration
acceleration is a
change in
velocity
slowing down is
also an acceleration
acceleration=change in
velocity(m/s) / time taken(s)
a=(v-u) / t
a=acceleration
v=final velocity
u=initial velocity
t=time taken
a velocity time graph
shows how the
velocity of an object
changes with time.
The distance can be
calculated from the
area under the line
a sloping line means
the object is
accelerating, a straight
line means the object is
moving at a constant
velocity, a line going
downwards means the
object is slowing down,
the highest point is the
objects final velocity
resultant forces
if there is more
than one force
on a object all
the forces can
be combined
into a resultant
force
a force is a vector quantity, because it
has a direction as well as a size
a free body diagram represents
the forces acting on an object
the arrows represent the size of the force
action and reaction forces need 2 objects
e.g kicking a ball
the force from the foot on the ball is the action force.
the ball exerts and equal opposite
reaction force on the foot
measured in
newtons (N)
forces and acceleration
newtons second law
if the forces on an object are unbalanced 2
things about an object can change. Its
speed or direction
force =mass x acceleration
f=ma
the greater the force,the greater the
acceleration for a constant mass
the greater the mass , the smaller the
acceleration for a constant force