Please enable JavaScript.
Coggle requires JavaScript to display documents.
P5 - Forces and Motion - End of Topic - Part 1 - Coggle Diagram
P5 - Forces and Motion - End of Topic - Part 1
L1 - Scalars and Vectors
A
scalar quantity
is a quantity with
only magnitude
; it
does not have direction
. Examples include:
speed, energy, mass, distance
.
A vector quantity is a
quantity
with
both direction and magnitude.
Examples include:
displacement, force, velocity, acceleration
.
L2 - Types of Forces
A
contact force
is a force in which
two objects make physical contact with each other
in order to exert a force. Examples include
friction, air resistance and normal contact.
A
non contact force
is a force in which
two objects do not need to physically touch
for a force to be exerted; the force
can happen at a distance
. Examples include
electrostatic, magnetic and gravitational.
L3 - Resultant Forces
When a
body experiences a force or several forces
, it will have a
resultant force
in a
particular direction
given that the forces are not of the same magnitude.
If there is a
resultant force of 0N
,
Newton's First Law states
that the object will
either remain stationary
(if it is already stationary) or
continue at the same velocity
(if already moving).
If there is a
resultant force on an object
, it will
cause the object to accelerate in a specific direction
(direction of force).
L4 - Mass and Weight
Mass
is a
measure of the amount of matter
within an object/number of particles within an object. It is
measured in Kg.
Weight
is a
force
and is the
result of a mass being present within a gravitational field.
Weight = Mass x Gravitational Field Strength
W = mg
Newtons = Kilograms x Newtons/Kilogram
An object's
centre of gravity/mass
is the
point at which an objects weight acts.
L5 - Work Done
When
energy is transferred
to a
different
energy
store
;
work is done.
Work done
is the
energy transferred
when a
force causes a displacement
of an object.
Work Done = Force x Displacement
W = Fs
Joules = Newtons x Metres
L6 - Hooke's Law
Hooke's Law
states that a
spring's extension is proportional
to the
force applied
to it.
Hooke's Law shows
a
relationship of direct proportion
up to a limit
of proportionality (a point where the
spring is deformed in a plastic manner
).
Required Practical Method:
Secure
a
clamp stand
to a surface.
-
Hang
the
spring
you would like to observe
on a clamp
on the clamp stand.
-
Secure
a
ruler
to the stand, ensure that the
"zero" point is aligned with the top of the spring.
The ruler should be parallel to the spring.
-
Measure the initial length
of the spring.
-
Apply the
first force increment
, a
mass carrier
could be used here.
-
Measure
the
new length
of the spring.
-
Subtract
the
initial value
from this to
obtain an extension
.
-
Continue
to
add masses
and
record the extension
they cause until the
limit of proportionality
has been reached.
Independent variable
:
Force
applied to spring
-
Dependant variable
:
Extension
of spring/new length
-
Control variables
:
Stiffness
of spring, force
increments
Force = Spring Constant x Extension
F = ke
Newtons = Newtons/Metre x Extension
L7 - Spring Calculations
Elastic Potential Energy = 0.5(Spring Constant(Extension^2))
Ee = 0.5(k(e^2))
Joules = 0.5(Newtons/Metre(Metres^2))
L8 - Pressure
Pressure = Force / Area
p = F / A
Pascals = Newtons / Metres^2
L9 - Pressure in a Fluid
Pressure = Density x Gravitational Field Strength x Height
p = ρgh
Pascals = Kilograms/Meter^3 x N/kg x Metres
Density
of
water
=
997kg/m^3
Pascals vases
-
Water levels remain constant
in a container,
no matter the shape
of each section of the container; this is because
pressure must be equal at all points
in the fluid. Pressure is
unaffected by area
,
density is constant and pressure is constant
so the
depth will be equal throughout.
L10 - Upthrust
Archimedes principle
states that when an
object is completely or partially submerged
, the
upthrust
acting on it is a force
equal to the weight of water
that the
object displaces.
Upthrust = Density x Volume x Gravitation Field Strength
U = ρVg
Newtons = kg/m^3 x Metres^3 x Newtons/Metre
L13 - Speed
Speed = Distance / Time
v = s / t
Metres/Second = Metres / Seconds
Walking
- 1.5m/s
Running
- 3.0m/s
Cycling
- 6.0m/s
Sound
- 330.0m/s
L14 - Distance Time Graphs
The
gradient on a distance time graph
is representative of the
speed
.
L15 - Velocity Time Graphs
The
gradient of a velocity time graph
is
representative of the acceleration
; a
negative gradient
implies that a
deceleration
is taking place.
The total
area under a velocity time graph
is the
total distance
travelled.