Shad Ahmad Physics
Topic 1 – Motion and Forces
1) Define a scalar quantity.
A scalar quantity has magnitude (size) but no specific direction.
2) Define a vector quantity.
A vector quantity has both magnitude (size) and a specific direction
3) Recall vector and scalar quantities, including:
Vector:
Force
Velocity
Displacement
Weight
Acceleration
Momentum
Scalar:
Speed
Distance
Mass
Energy
Temperature
Time
4) Define velocity.
The speed in a stated direction (it’s a vector quantity).
5) What is the equation for distance?
,Shad Ahmad Physics
6) Analyse distance/time graphs.
The gradient (slope) at any point gives the speed of the object.
Flat sections are where it’s stopped.
A steeper graph means it’s going faster.
Curves represent accelerations.
Curve getting steeper means it’s speeding up (increasing gradient).
A levelling off curve means it’s slowing down (decreasing gradient).
7) What is the equation for acceleration?
8) What is the equation for uniform (constant) acceleration?
9) Analyse velocity/time graphs.
Gradient = acceleration
Flat sections represent a steady speed.
The steeper the graph, the greater the acceleration or deceleration.
Uphill sections (/) are acceleration.
Downhill sections (\) are deceleration.
A curve means changing acceleration.
Distance travelled is the area under the graph.
10) Describe a range of laboratory methods for determining the speeds of objects.
Light gates get rid of human error caused by reaction times – good for short time intervals.
Rolling tape measures, markers and a stopwatch to find something like someone’s walking
speed.
Record video of moving object and look how far it travels each frame – know how many
frames per second the camera records -> you can find the distance travelled by the object in
a given number of frames, and time it takes.
,Shad Ahmad Physics
11) Recall some typical speeds encountered in everyday experience for wind and sound, and for
walking, running, cycling and other transportation systems.
Walking = 1.4 m/s
Running = 3 m/s
Cycling = 5.5 m/s
Cars in a built-up area = 13m/s
Cars on a motorway = 31 m/s
Trains = 55 m/s
Aeroplanes = 250 m/s
Wind speed = 5-20m/s
Speed of sound in air = 343 m/s
Ferries = 15 m/s
12) What is the acceleration due to gravity (its uniform for objects) in free fall?
9.8 m/s2 (roughly 10 m/s2)
13) Recall Newton’s first law and use it in the following situations:
If the resultant force on a stationary object is 0, the object will remain stationary.
If the resultant force on a moving object is 0, it’ll carry on moving at the same velocity.
The velocity will only change if there is a non-zero resultant force acting on the object, producing
acceleration in the direction of the force.
14) Recall Newton’s second law.
The force and the acceleration are directly proportional.
Acceleration is inversely proportional to mass of the object.
15) What is the equation for weight?
, Shad Ahmad Physics
16) Describe what weight is, and how it is measured.
Weight is the force acting on an object due to gravity. Weight is measured in newtons. Gravitational
field strength varies with location (stronger the closer you are to the mass causing the field). This
means weight of an object changes with its location.
17) Core Practical: Investigate the relationship between force, mass and acceleration by varying
the masses added to trolleys.
1. Measure mass of trolley, unit masses and hanging hook.
2. Measure length of piece of card (that will interrupt light gate beams).
3. Set up apparatus.
4. Adjust height of ramp until trolley just starts to move.
5. Mark a line on the ramp just before the first light gate (ensures trolley travels same distance
each time). Light gate records the initial speed of trolley as it begins to move.
6. Attach trolley to hanging mass by the string. Hold trolley still at start line, then let go.
7. Each light gate records time when trolley passes through it and speed of trolley at that time.
Then use acceleration = change in speed / time.
Investigate effect of trolley’s mass: Add masses one at a time to the trolley. Keep the mass
on the hook constant (so accelerating force is constant).
Investigate effect of accelerating force: All masses loaded onto the trolley and transfer the
masses to the hook one at a time.
As accelerating force increases, acceleration increases, so force and acceleration are
proportional.
As mass of trolley increases, acceleration decreases – mass and acceleration inversely
proportional.
18) Explain that an object moving in a circular orbit at constant speed has a changing velocity.
Velocity is both the speed and direction. If an object is travelling in a circle (at constant speed), its
constantly changing velocity, meaning its accelerating.
19) Explain centripetal force.
Centripetal force is the force that keeps something moving in a circle. It is the resultant force that
acts towards the centre of the circle.
20) Explain inertia and inertial mass.
Inertia = the tendency to keep moving with the same velocity.
Inertial mass = Measures how difficult it is to change the velocity of an object.
Inertial mass is the ratio of force over acceleration.
Topic 1 – Motion and Forces
1) Define a scalar quantity.
A scalar quantity has magnitude (size) but no specific direction.
2) Define a vector quantity.
A vector quantity has both magnitude (size) and a specific direction
3) Recall vector and scalar quantities, including:
Vector:
Force
Velocity
Displacement
Weight
Acceleration
Momentum
Scalar:
Speed
Distance
Mass
Energy
Temperature
Time
4) Define velocity.
The speed in a stated direction (it’s a vector quantity).
5) What is the equation for distance?
,Shad Ahmad Physics
6) Analyse distance/time graphs.
The gradient (slope) at any point gives the speed of the object.
Flat sections are where it’s stopped.
A steeper graph means it’s going faster.
Curves represent accelerations.
Curve getting steeper means it’s speeding up (increasing gradient).
A levelling off curve means it’s slowing down (decreasing gradient).
7) What is the equation for acceleration?
8) What is the equation for uniform (constant) acceleration?
9) Analyse velocity/time graphs.
Gradient = acceleration
Flat sections represent a steady speed.
The steeper the graph, the greater the acceleration or deceleration.
Uphill sections (/) are acceleration.
Downhill sections (\) are deceleration.
A curve means changing acceleration.
Distance travelled is the area under the graph.
10) Describe a range of laboratory methods for determining the speeds of objects.
Light gates get rid of human error caused by reaction times – good for short time intervals.
Rolling tape measures, markers and a stopwatch to find something like someone’s walking
speed.
Record video of moving object and look how far it travels each frame – know how many
frames per second the camera records -> you can find the distance travelled by the object in
a given number of frames, and time it takes.
,Shad Ahmad Physics
11) Recall some typical speeds encountered in everyday experience for wind and sound, and for
walking, running, cycling and other transportation systems.
Walking = 1.4 m/s
Running = 3 m/s
Cycling = 5.5 m/s
Cars in a built-up area = 13m/s
Cars on a motorway = 31 m/s
Trains = 55 m/s
Aeroplanes = 250 m/s
Wind speed = 5-20m/s
Speed of sound in air = 343 m/s
Ferries = 15 m/s
12) What is the acceleration due to gravity (its uniform for objects) in free fall?
9.8 m/s2 (roughly 10 m/s2)
13) Recall Newton’s first law and use it in the following situations:
If the resultant force on a stationary object is 0, the object will remain stationary.
If the resultant force on a moving object is 0, it’ll carry on moving at the same velocity.
The velocity will only change if there is a non-zero resultant force acting on the object, producing
acceleration in the direction of the force.
14) Recall Newton’s second law.
The force and the acceleration are directly proportional.
Acceleration is inversely proportional to mass of the object.
15) What is the equation for weight?
, Shad Ahmad Physics
16) Describe what weight is, and how it is measured.
Weight is the force acting on an object due to gravity. Weight is measured in newtons. Gravitational
field strength varies with location (stronger the closer you are to the mass causing the field). This
means weight of an object changes with its location.
17) Core Practical: Investigate the relationship between force, mass and acceleration by varying
the masses added to trolleys.
1. Measure mass of trolley, unit masses and hanging hook.
2. Measure length of piece of card (that will interrupt light gate beams).
3. Set up apparatus.
4. Adjust height of ramp until trolley just starts to move.
5. Mark a line on the ramp just before the first light gate (ensures trolley travels same distance
each time). Light gate records the initial speed of trolley as it begins to move.
6. Attach trolley to hanging mass by the string. Hold trolley still at start line, then let go.
7. Each light gate records time when trolley passes through it and speed of trolley at that time.
Then use acceleration = change in speed / time.
Investigate effect of trolley’s mass: Add masses one at a time to the trolley. Keep the mass
on the hook constant (so accelerating force is constant).
Investigate effect of accelerating force: All masses loaded onto the trolley and transfer the
masses to the hook one at a time.
As accelerating force increases, acceleration increases, so force and acceleration are
proportional.
As mass of trolley increases, acceleration decreases – mass and acceleration inversely
proportional.
18) Explain that an object moving in a circular orbit at constant speed has a changing velocity.
Velocity is both the speed and direction. If an object is travelling in a circle (at constant speed), its
constantly changing velocity, meaning its accelerating.
19) Explain centripetal force.
Centripetal force is the force that keeps something moving in a circle. It is the resultant force that
acts towards the centre of the circle.
20) Explain inertia and inertial mass.
Inertia = the tendency to keep moving with the same velocity.
Inertial mass = Measures how difficult it is to change the velocity of an object.
Inertial mass is the ratio of force over acceleration.
