National 5 PhysicsDynamics and SpacePupil notes Done in class

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Assessed
Pupil notes
Revised
Dynamics and Space
Done in class
National 5 Physics
I can describe vector and scalar quantities, and
identify them.
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A scalar quantity has magnitude only
A vector quantity has both magnitude and direction.
Scalar quantities: speed, distance, mass, time, energy
Vector quantities: velocity, displacement, weight, force, acceleration
I can calculate the resultant of two vectors
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Vectors are added “tip-to-tail”
The resultant vector is measured from the start of the first vector
to the end of the last vector.
All resultant vectors must have a three figure bearing, measured
from 000˚ (North)
National 5 Physics
Dynamics and Space
Pupil notes
I can use a scale diagram or calculation to find a
resultant displacement
N (000˚)
W (270˚)
E (090˚)
S (180˚)
In the above example, the distance travelled is 19km, but to work out
displacement, we use a scale drawing.
Scale diagram drawing tips:
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Draw a mini compass.
Choose a suitable scale- make it big enough to measure
displacement accurately. Write this scale down.
- e.g. 1cm:1km
Measure your displacement bearing from where you finish, not
where you started from (common mistake).
To avoid mistakes, quote bearings as a three figure-number.
National 5 Physics
Dynamics and Space
Pupil notes
I understand the difference between ‘speed’ and
‘velocity’
𝑑 =𝑣×𝑡
‘distance’ and ‘speed’ are scalar quantities
and require a magnitude only.
where
d = distance (measured in metres, m)
v = speed (measured in metres per second, ms-1)
t = time (measured in seconds, s)
𝑠 =𝑣×𝑡
‘displacement’ and ‘velocity’ are vector quantities
and require both magnitude and direction.
where
s = displacement (measured in metres, m) and direction
v = velocity (measured in metres per second, ms-1) and direction
t = time (measured in seconds, s)
National 5 Physics
Dynamics and Space
Pupil notes
I know how to get information from velocity-time
graphs
Car is speeding up (accelerating) from O to A
Velocity (ms-1)
Car is going at a constant speed from A to B
Car is slowing down (decelerating) from B to C
Displacement = Area under velocity-time graph
I can use the formula which links acceleration,
change in speed and time, and calculate
acceleration from a velocity-time graph.
𝑎=
𝑣−𝑢
𝑡
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑐ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑠𝑝𝑒𝑒𝑑
𝑡𝑖𝑚𝑒
where
a = acceleration (measured in metres per second squared, ms-2)
v = final speed (measured in metres per second, ms-1)
u = initial speed (measured in metres per second, ms-1)
t = time (measured in seconds, s)
National 5 Physics
Dynamics and Space
Pupil notes
I know what is meant by a ‘Force’
A ‘Force’ can change the speed, direction or shape of an
object.
Force can be measured using a newton balance.
Force is measured in Newtons (N).
I know that ‘friction’ is a type of force.
Friction is caused by two objects moving while in contact with each other.
The force of friction is always in the opposite direction to movement.
Air resistance and drag are also types of frictional forces.
I can describe some ways in which we can reduce
frictional forces
Streamlining
Lubrication
Smoothing surfaces
National 5 Physics
Dynamics and Space
Pupil notes
I know what is meant by ‘balanced forces’
If two forces are the same size but act in opposite directions, they are
known as balanced forces.
I understand what Newton’s 1st law tells us about
balanced forces and velocity
If the forces on an object are balanced, then the object will either

stay at rest (not move)
or
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will move with a constant velocity in a straight line.
I can calculate the ‘unbalanced force’ if given two
different forces in opposite directions
I understand what Newton’s 2nd law tells us about
unbalanced forces and acceleration.
If the forces on an object are unbalanced, then there is more force
acting in one direction than the other.
The object will accelerate in the direction of the unbalanced force.
National 5 Physics
Dynamics and Space
Pupil notes
I can use the formula which links unbalanced
force, mass and acceleration
𝐹 =𝑚×𝑎
where
Fun = unbalanced force (measured in Newtons, N)
m = mass (measured in kilograms, kg)
a = acceleration (measured in metres per second squared, ms-2)
I can use the formula which links Work done,
unbalanced force and distance
𝑊 =𝐹×𝑑
where
W = work done, or work energy (measured in Joules, J)
F = unbalanced force (measured in Newtons, N)
d = distance (measured in metres, m)
National 5 Physics
Dynamics and Space
Pupil notes
I know the difference between the mass of an
object and its weight
Mass is a measure of the amount of ‘stuff’ that makes up an object, and
is measured in kilograms.
Weight is force acting downwards on an object caused by gravity, and is
measured in Newtons.
The weight of an object may be different on different bodies in our solar
system, but the mass remains the same everywhere.
I can use the formula which links weight, mass
and gravitational field strength for different
objects in our solar system
𝑊 =𝑚×𝑔
where
W = Weight (measured in Newtons, N)
m = mass (measured in kilograms, kg)
g = gravitational field strength (measured in Newtons per kilogram,
Nkg-1)
National 5 Physics
Dynamics and Space
Pupil notes
I understand what Newton’s 3rd law tells us about
action and reaction forces
For every ‘action’ (Force) there is an equal and opposite reaction (Force.)
]
I understand ‘Free fall’ and ‘Terminal velocity’ in
terms of Newton’s laws and Friction.
Free fall: Weight of a falling object acts downwards, but there is no
‘reaction force’ acting upwards on the object, giving the sensation of
‘weightlessness.’
Terminal velocity: An accelerating falling object will experience frictional
forces which increase until balanced with the object’s weight, which
results in a constant speed called terminal velocity.
Air Resistance acting upwards
No reaction force
on diver, so he
feels weightless.
When air resistance balances
weight, terminal velocity is
reached.
Weight acting downwards
National 5 Physics
Dynamics and Space
Pupil notes
I understand what is meant by ‘projectile motion.’
A projectile is an object which is moving only under the influence of
gravity, and falls to Earth with a curved path.
Projectiles move with a constant horizontal velocity, but accelerate at
the same time vertically.
Notice how, after each second, the cannonball has travelled the same
distance horizontally but travels a greater distance each second vertically.
I can perform calculations involving projectile
motion from a horizontal launch.
From a horizontal launch:
v = constant horizontally.
u = 0 ms-1 vertically.
a = 9.8 ms-2 vertically downwards.
Top tip: split your page in two down the middle
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
one side for horizontal motion
the other for vertical motion.
Horizontal
Vertical
d = 100m
a = 9.8 ms-1
v = 10 ms-1
v =?
t=?
u = 0 ms-1
t =?
National 5 Physics
Dynamics and Space
Pupil notes
I can explain the orbit of a satellite in terms of
projectile motion
A satellite, after launch, will begin to fall towards earth with a curved
path, just like any projectile. If launched with enough velocity, the curved
path will extend beyond the curvature of the earth, and the satellite will
continue to follow that curved path around the earth. This is how a
satellite stays in orbit.
I can describe some of the risks and benefits of
space exploration
Risks
Re-entry to a planet’s atmosphere is challenging because
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It creates a large amount of heat due to air resistance. Thermal
protection systems must be used to ensure the spacecraft is
protected on re-entry.
The angle of re-entry must be precisely calculated so the spacecraft
doesn’t ‘bounce off’ the atmosphere.
Benefits
Space exploration has helped to develop
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The accuracy of weather forecasting
Telecommunications via Satellites
Analysis of our environment
National security
Sat-Nav systems
Robotics
National 5 Physics
Dynamics and Space
Pupil notes
I can discuss the impact that space exploration
has had on our understanding of the universe and
of planet Earth
Space telescopes (e.g. Hubble), Space probes (e.g. Voyager) and Space
rovers (e.g. Spirit) have all contributed to our understanding of the
universe in different ways. For example:
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Hubble’s deep field lens allows us to capture images across many
wavelengths of EM radiation from deep space.
Voyager has performed ‘fly pasts’ of many objects in our solar
system giving up close, detailed images never seen before.
Spirit analysed the terrain on Mars to help determine if life had ever
existed there.
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I know that large distances in space are
measured in light years.
A light year is the distance that light will travel in one year:
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One light year = 9.5 x1015 metres.
Our solar system measures only a small fraction of a light year, yet the
universe measures many billions of light years.
National 5 Physics
Dynamics and Space
Pupil notes
I know what is meant by the ‘observable universe’
and what it tells us about the origin and age of
the universe
Since light travels at a finite speed, it takes some time to get to us. If an
object is far enough away, its light may not have reached us yet.
The furthest point that we can ‘see’ is the distance which light must have
travelled for the whole age of the universe. This distance is called the
‘observable universe.’
This means that we can calculate the age of the universe- estimated to be
just less than 14 billion years old.
The universe is constantly expanding- objects are getting further apart.
This suggests that all matter in the universe has all been expanding from
a single point- an expansion started by the big bang.
I know that different objects in the universe can
be detected using different parts of the
electromagnetic spectrum.
Some objects in the universe cannot be detected using ‘visible’ light, and
look dark when viewed with optical telescopes.
However, these objects often emit radiation in the form of Infrared,
Ultraviolet, X-rays or gamma rays, which can be detected by using
specialised telescopes.
National 5 Physics
Dynamics and Space
Pupil notes
I can identify a continuous spectrum and a line
spectrum
White light sources, when ‘split up’ using a prism or viewed through a
spectroscope will produce a ‘continuous spectrum’ of colours
(ROY G BIV).
Other light sources (such as fluorescent ‘strip’ lamps) will instead produce
a ‘line spectrum’ when viewed through a spectroscope, where not all the
colours are present.
NB: One of these is called a ‘spectrum’ and more than one of these are
called ‘spectra’.
I can use ‘line spectra’ to identify the elements
present in stars
Different elements emit different wavelengths (colours) of light depending
on their atomic structure. These act as an ‘atomic fingerprint’ that can
identify the element.
Looking at light coming from a star using a spectroscope will identify the
elements in that star.
The line spectrum for Hydrogen
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