Unit 1
Chapter 1
Movement and Position
Distance: scalar quantity that refers to the total length an object has travelled
Displacement: vector quantity that refers to the distance an object has travelled in a particular
direction
Speed: the rate of change in distance
distance moved/ time taken (m/s)
Velocity: the rate of change in displacement
displacement/ time taken (m/s)
Acceleration: rate of change in velocity
Change in velocity/ time take (m/s^2)
Uniformly accelerated motion: (final speed)^2 = (initial speed)^2 + (2 * acceleration * distance)
Distance-Time graphs
1) The steeper the line the faster it is
2) The speed can be determined by gradient
3) If the line is horizontal it’s stationary
4) If gradient changes so does the speed
5) If distance is decreasing it’s going backward
Velocity-Time graphs
1) The shallower the gradient the less
acceleration
2) If it’s horizontal then it’s moving at a
constant speed
3) If the gradient is negative then it’s
decelerating
4) The area underneath gives us the distance
travelled
A piece of soft material is fixed to the front of the
toy car.
Explain how this will affect the gradient of the velocity‑time graph after the car hits the block.
increases time of collision;
any reference to shallower gradient on graph;
so acceleration will be smaller (in magnitude);
Practical
DV: time, IDV: distance, CV: same object
,Method:
1) Measure out a height of 1.0 m using the tape measure or metre ruler
2) Drop the object (paper cone or tennis ball) from this height, which is the distance travelled by
the object
3) Use the stop clock to measure how long the object takes to travel this distance
4) Record the distance travelled and time taken
5) Repeat steps 2-3 three times, calculating an average time taken for the object to fall a certain
distance
6) Repeat steps 1-4 for height
7) Make sure the measurements on the tape
measure or metre rule are taken at eye level to
avoid parallax error
8) Consider using an electronic sensor, such as light
gates, to obtain highly accurate measurements of
time
a) Once the object is released, the timer
starts and stops automatically as it
reaches the sensor on the ground
9) Ensure the experiment is done in a space with no
draught or breeze, as this could affect the motion
of the falling object
10) Using a ball bearing and an electronic data
logger, like a trap door, is a good way to remove
the error due to human reaction time for this
experiment
11) Place a mat or a soft material below any falling
object to cushion its fall
The photograph shows a toy train as it moves around a circular track.
A student wants to find the average speed of the toy train.
Describe a method that the student could use to find the average speed.
MP1. determine / measure distance; allow idea of measuring diameter/radius and calculating distance
MP2. determine / measure time;
MP3. appropriate measuring instrument for distance OR time;
MP4. use a suitable distance / count laps (of known length);
MP5. repeat experiment and calculate average;
MP6. use of speed = distance ÷ time;
MP7. suitable experimental precaution e.g. reaction time considered, time from and to predetermined
points;
Chapter 2
Forces and Shape
Forces
Vector quantity (has both a magnitude and a direction, as opposed to being a scalar quantity which
only has a magnitude)
Result in a change in speed, shape or direction
Measured in N
Examples:
1) Gravitational (or weight) - the force between any two objects with mass (like the Earth and the
Moon)
2) Electrostatic - the force between any two objects with charge (like a proton and an electron)
3) Thrust - the force pushing a vehicle (like the push from rocket engines on the shuttle)
, 4) Upthrust - the upward force on any object in a fluid (like a boat on the surface of a river)
5) Air resistance (or drag) - the force of friction between objects falling through the air (like a
skydiver in freefall)
6) Compression - forces that squeeze an object (like squeezing a spring)
7) Tension - forces that stretch an object (like two teams in a tug-of-war)
8) Reaction force - the force between any two objects in contact (like the upwards force from a
table on a book)
9) Friction - force between two surfaces which impedes motion and results in heating
Newton’s Laws
1st, an object has a constant velocity unless it's being acted on by a resultant force (=total effect of two
or more forces acting on an object)
2nd, F=m*a
3rd, every action has an equal and opposite reaction
Hooke’s Law
idea that extension is (directly) proportional to force or
load;
up to limit of proportionality;
The extension of an elastic object is directly proportional
to the force applied, up to the limit of proportionality
Elastic bands to not obey Hooke’s law, as the graph is
nonlinear and the extension for the same force may be
different
Elastic Deformation is when objects return to their
original shape when the stretching force is removed
Inelastic Deformation is when objects remain stretched and do not return completely to their original
shape even when the stretching force is removed
Practical
IDV: force, DV: extension
1) Set up the apparatus as shown in the diagram,
initially without any masses hanging from the spring
/ rubber band
2) Align the marker to a value on the ruler, record this
initial length of the spring / rubber band
3) Add the 100 g mass hanger onto the spring / rubber
band
, 4) Record the mass (in kg) and position (in cm) from the ruler now that the spring / rubber band
has extended Add another 100 g to the mass hanger
5) Record the new mass and position from the ruler now that the spring / rubber band has
extended further
6) Repeat this process until all masses have been added
7) Remove the masses and repeat the entire process again, until it has been carried out a total of
three times, and an average length (for each mass attached) is calculated
8) Make sure the measurements on the ruler are taken at eye level to avoid parallax error
9) The accuracy of such an experiment is improved with the use of a pointer (a fiducial marker)
10) Wait a few seconds for the spring / rubber band / metal wire to fully extend when a mass is
added, before taking the reading for its new length
11) Make sure to check whether the spring has not gone past its limit of proportionality otherwise,
it has been stretched too far
12) Wear goggles during this experiment in case the spring snaps
13) Stand up while carrying out the experiment making sure no feet are directly under the masses
14) Place a mat or a soft material below the masses to prevent any damage in case they fall
Chapter 3
Forces and Movement
F=m*a in N
W=m*g
Objects will remain at rest, or move with a constant velocity unless acted on by a resultant force
Stopping a Car
Stopping distance: The total distance travelled during the time it takes for a car to stop in response to
some emergency
Thinking distance: the distance travelled from the moment the driver sees the hazard to the moment
he presses his breaks
Braking distance: the distance travelled from the moment the brakes are applied to the moment the
car comes to a halt
Factors affecting:
1) Thinking Distance: Tiredness, Distractions (e.g. using a mobile phone), Intoxication (i.e.
consumption of alcohol or drugs), Vision
2) Braking Distance: Vehicle condition – e.g. worn tyres or poor brakes, Road condition – wet or
icy roads make it harder to decelerate, Vehicle mass – a heavy vehicle, such as a lorry, takes
longer to stop
Terminal velocity
the maximum velocity it can reach when all the forces
are balanced.
Initially, the upwards air resistance is very small
because the skydiver isn't falling very quickly
Therefore, there are unbalanced forces on the skydiver
initially
As the skydiver speeds up, air resistance increases,
eventually growing large enough to balance the
downwards weight force
Once air resistance equals weight, the forces are
balanced
Chapter 1
Movement and Position
Distance: scalar quantity that refers to the total length an object has travelled
Displacement: vector quantity that refers to the distance an object has travelled in a particular
direction
Speed: the rate of change in distance
distance moved/ time taken (m/s)
Velocity: the rate of change in displacement
displacement/ time taken (m/s)
Acceleration: rate of change in velocity
Change in velocity/ time take (m/s^2)
Uniformly accelerated motion: (final speed)^2 = (initial speed)^2 + (2 * acceleration * distance)
Distance-Time graphs
1) The steeper the line the faster it is
2) The speed can be determined by gradient
3) If the line is horizontal it’s stationary
4) If gradient changes so does the speed
5) If distance is decreasing it’s going backward
Velocity-Time graphs
1) The shallower the gradient the less
acceleration
2) If it’s horizontal then it’s moving at a
constant speed
3) If the gradient is negative then it’s
decelerating
4) The area underneath gives us the distance
travelled
A piece of soft material is fixed to the front of the
toy car.
Explain how this will affect the gradient of the velocity‑time graph after the car hits the block.
increases time of collision;
any reference to shallower gradient on graph;
so acceleration will be smaller (in magnitude);
Practical
DV: time, IDV: distance, CV: same object
,Method:
1) Measure out a height of 1.0 m using the tape measure or metre ruler
2) Drop the object (paper cone or tennis ball) from this height, which is the distance travelled by
the object
3) Use the stop clock to measure how long the object takes to travel this distance
4) Record the distance travelled and time taken
5) Repeat steps 2-3 three times, calculating an average time taken for the object to fall a certain
distance
6) Repeat steps 1-4 for height
7) Make sure the measurements on the tape
measure or metre rule are taken at eye level to
avoid parallax error
8) Consider using an electronic sensor, such as light
gates, to obtain highly accurate measurements of
time
a) Once the object is released, the timer
starts and stops automatically as it
reaches the sensor on the ground
9) Ensure the experiment is done in a space with no
draught or breeze, as this could affect the motion
of the falling object
10) Using a ball bearing and an electronic data
logger, like a trap door, is a good way to remove
the error due to human reaction time for this
experiment
11) Place a mat or a soft material below any falling
object to cushion its fall
The photograph shows a toy train as it moves around a circular track.
A student wants to find the average speed of the toy train.
Describe a method that the student could use to find the average speed.
MP1. determine / measure distance; allow idea of measuring diameter/radius and calculating distance
MP2. determine / measure time;
MP3. appropriate measuring instrument for distance OR time;
MP4. use a suitable distance / count laps (of known length);
MP5. repeat experiment and calculate average;
MP6. use of speed = distance ÷ time;
MP7. suitable experimental precaution e.g. reaction time considered, time from and to predetermined
points;
Chapter 2
Forces and Shape
Forces
Vector quantity (has both a magnitude and a direction, as opposed to being a scalar quantity which
only has a magnitude)
Result in a change in speed, shape or direction
Measured in N
Examples:
1) Gravitational (or weight) - the force between any two objects with mass (like the Earth and the
Moon)
2) Electrostatic - the force between any two objects with charge (like a proton and an electron)
3) Thrust - the force pushing a vehicle (like the push from rocket engines on the shuttle)
, 4) Upthrust - the upward force on any object in a fluid (like a boat on the surface of a river)
5) Air resistance (or drag) - the force of friction between objects falling through the air (like a
skydiver in freefall)
6) Compression - forces that squeeze an object (like squeezing a spring)
7) Tension - forces that stretch an object (like two teams in a tug-of-war)
8) Reaction force - the force between any two objects in contact (like the upwards force from a
table on a book)
9) Friction - force between two surfaces which impedes motion and results in heating
Newton’s Laws
1st, an object has a constant velocity unless it's being acted on by a resultant force (=total effect of two
or more forces acting on an object)
2nd, F=m*a
3rd, every action has an equal and opposite reaction
Hooke’s Law
idea that extension is (directly) proportional to force or
load;
up to limit of proportionality;
The extension of an elastic object is directly proportional
to the force applied, up to the limit of proportionality
Elastic bands to not obey Hooke’s law, as the graph is
nonlinear and the extension for the same force may be
different
Elastic Deformation is when objects return to their
original shape when the stretching force is removed
Inelastic Deformation is when objects remain stretched and do not return completely to their original
shape even when the stretching force is removed
Practical
IDV: force, DV: extension
1) Set up the apparatus as shown in the diagram,
initially without any masses hanging from the spring
/ rubber band
2) Align the marker to a value on the ruler, record this
initial length of the spring / rubber band
3) Add the 100 g mass hanger onto the spring / rubber
band
, 4) Record the mass (in kg) and position (in cm) from the ruler now that the spring / rubber band
has extended Add another 100 g to the mass hanger
5) Record the new mass and position from the ruler now that the spring / rubber band has
extended further
6) Repeat this process until all masses have been added
7) Remove the masses and repeat the entire process again, until it has been carried out a total of
three times, and an average length (for each mass attached) is calculated
8) Make sure the measurements on the ruler are taken at eye level to avoid parallax error
9) The accuracy of such an experiment is improved with the use of a pointer (a fiducial marker)
10) Wait a few seconds for the spring / rubber band / metal wire to fully extend when a mass is
added, before taking the reading for its new length
11) Make sure to check whether the spring has not gone past its limit of proportionality otherwise,
it has been stretched too far
12) Wear goggles during this experiment in case the spring snaps
13) Stand up while carrying out the experiment making sure no feet are directly under the masses
14) Place a mat or a soft material below the masses to prevent any damage in case they fall
Chapter 3
Forces and Movement
F=m*a in N
W=m*g
Objects will remain at rest, or move with a constant velocity unless acted on by a resultant force
Stopping a Car
Stopping distance: The total distance travelled during the time it takes for a car to stop in response to
some emergency
Thinking distance: the distance travelled from the moment the driver sees the hazard to the moment
he presses his breaks
Braking distance: the distance travelled from the moment the brakes are applied to the moment the
car comes to a halt
Factors affecting:
1) Thinking Distance: Tiredness, Distractions (e.g. using a mobile phone), Intoxication (i.e.
consumption of alcohol or drugs), Vision
2) Braking Distance: Vehicle condition – e.g. worn tyres or poor brakes, Road condition – wet or
icy roads make it harder to decelerate, Vehicle mass – a heavy vehicle, such as a lorry, takes
longer to stop
Terminal velocity
the maximum velocity it can reach when all the forces
are balanced.
Initially, the upwards air resistance is very small
because the skydiver isn't falling very quickly
Therefore, there are unbalanced forces on the skydiver
initially
As the skydiver speeds up, air resistance increases,
eventually growing large enough to balance the
downwards weight force
Once air resistance equals weight, the forces are
balanced
