Define scalar quantity.

A scalar quantity has only a magnitude (size), with no direction, for example mass or distance .

Define vector quantity.

A vector quantity has both magnitude and direction , for example velocity or displacement .

What is the difference between distance and displacement ?

Distance is the total length of the path travelled, with no direction (scalar). Displacement is how far an object is from its starting point, in a straight line, including direction (vector).

In a 300 m race where the finish line is 100 m to the right of the start, what are the athletes' distance travelled and their displacement?

Distance travelled = 300 m. Displacement = 100 m to the right of the start.

Explain why mass is a scalar quantity but weight is a vector quantity.

Mass has magnitude only, so it is a scalar. Weight is a force with both magnitude and direction (due to gravity), so it is a vector.

If athletes run a full 400 m lap and return to their starting point, their total distance is 400 m but their ______ is zero.

If athletes run a full 400 m lap and return to their starting point, their total distance is 400 m but their displacement is zero.

True or False? Speed and velocity are both scalar quantities.

False. Speed is a scalar quantity, but velocity is a vector quantity because it also includes a direction.

Speed is the distance an object travels every second; it is a scalar quantity because it has magnitude only.

A plane flies at an average speed of 250 m/s for 2 hours. Calculate the total distance it travels.

Time = 2 × 60 × 60 = 7200 s. Distance = 250 × 7200 = 1 800 000 m .

When using a formula triangle, covering up the quantity you want to calculate is known as finding the ______ of the equation.

When using a formula triangle, covering up the quantity you want to calculate is known as finding the subject of the equation.

True or False? Speed is a vector quantity.

False. Speed is a scalar quantity because it only has magnitude, with no direction.

Velocity is the speed of an object in a stated direction — a vector quantity, since it has both magnitude and direction.

What two pieces of information must be given to fully describe an object's velocity?

A magnitude (speed) and a direction , for example " 15 m/s south " or " 250 mph on a bearing of 030° ".

Two cars travelling in different lanes at the same speed but in different directions have the same speed but different ______ .

Two cars travelling in different lanes at the same speed but in different directions have the same speed but different velocities .

True or False? Speed is a vector quantity.

False. Speed is a scalar quantity; velocity is the vector quantity, since it also includes a direction.

A car's motion is described only as "15 m/s". Is this a speed or a velocity? Explain your answer.

This describes a speed , since only a magnitude is given. To describe a velocity , a direction would also need to be stated, for example "15 m/s south".

What does a distance-time graph show?

How the distance travelled by an object moving in a straight line changes over time .

What does a flat, horizontal line on a distance-time graph represent?

The object is stationary (not moving).

How can you tell whether an object is moving with a large or small speed from the slope of a straight line on a distance-time graph?

A steep slope represents a large speed; a shallow slope represents a small speed.

What does a curved line on a distance-time graph represent, and how do you tell if the object is speeding up or slowing down?

A curve represents a changing speed . An increasing slope means the object is speeding up ; a decreasing slope means it is slowing down .

The speed of a moving object can be calculated from the ______ of the line on a distance-time graph.

The speed of a moving object can be calculated from the gradient of the line on a distance-time graph.

True or False? A straight, sloped line on a distance-time graph represents an object that is stationary.

False. A straight, sloped line represents constant speed . Only a flat, horizontal line represents a stationary object.

A train travels 8 km in 6 minutes at a constant speed. Calculate its speed in m/s.

Distance = 8000 m, time = 360 s. Speed = 8000 ÷ 360 = 22.2 m/s .

Define acceleration .

Acceleration is the rate of change of velocity — how much an object's velocity changes every second.

True or False? A negative value of acceleration means an object is speeding up.

False. A negative acceleration (deceleration) means the object is slowing down ; a positive acceleration means it is speeding up.

Define the acceleration due to gravity , g .

In the absence of air resistance , all objects near Earth's surface fall with the same acceleration, g = 10 m/s² .

In freefall, with no air resistance, an object's velocity increases by ______ for every second it falls.

In freefall, with no air resistance, an object's velocity increases by 10 m/s for every second it falls.

Define velocity-time graph .

A velocity-time graph shows how the velocity of a moving object varies with time .

What does a straight line on a velocity-time graph represent?

A straight line represents constant acceleration (or deceleration); the slope of the line shows the magnitude of the acceleration.

How does the steepness of the slope on a velocity-time graph relate to the object's acceleration?

A steep slope means a large acceleration (speed changes quickly) A gentle slope means a small acceleration (speed changes gradually) A flat line means zero acceleration (constant velocity)

On a velocity-time graph, a ______ line means the object is moving at a constant velocity.

On a velocity-time graph, a flat line means the object is moving at a constant velocity.

True or False? A steep slope on a velocity-time graph means the object's speed changes slowly.

False. A steep slope means a large acceleration , so speed changes quickly ; a gentle slope means the speed changes gradually .

What does the area under a velocity-time graph represent?

The displacement (or distance travelled ) by the object.

How is the area under a velocity-time graph calculated when the enclosed shape is a triangle ?

Area = ½ × base × height , used when the object is accelerating or decelerating .

How is the area under a velocity-time graph calculated when the enclosed shape is a rectangle ?

Area = base × height , used when the object is moving at a constant velocity .

If a velocity-time graph consists of straight-line sections, the total distance travelled is found by adding the areas of the enclosed rectangles and ______ .

If a velocity-time graph consists of straight-line sections, the total distance travelled is found by adding the areas of the enclosed rectangles and triangles .

True or False? The area under a velocity-time graph gives the acceleration of the object.

False. The area gives the displacement (or distance travelled); the gradient gives the acceleration.

Name three factors that can affect a person's typical walking speed .

Age Terrain Fitness Distance (length of the journey)

What piece of equipment is most appropriate for measuring a long distance, such as an athletics track?

A trundle wheel (or a long tape measure).

How does a single light gate measure the speed of an object passing through it?

A flag attached to the object blocks the light beam as it passes; the timer records how long the beam is blocked; the distance travelled is the length of the flag , so speed can be calculated from distance ÷ time.

A light gate can be used to ______ a timer when an object passes through it, using a flag to block the light beam.

A light gate can be used to start a timer when an object passes through it, using a flag to block the light beam.

True or False? The typical walking speed of a person is about 6 m/s.

False. The typical walking speed is about 1.5 m/s ; 6 m/s would be far too fast for typical walking.

GCSEPhysicsEdexcelFlashcards2. Motion & ForcesDescribing Motion

Describing Motion (Edexcel GCSE Physics): Flashcards

Exam code: 1PH0

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Define scalar quantity.

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Cards in this collection (58)

Define scalar quantity.
A scalar quantity has only a magnitude (size), with no direction, for example mass or distance.
Define vector quantity.
A vector quantity has both magnitude and direction, for example velocity or displacement.
What is the difference between distance and displacement?
Distance is the total length of the path travelled, with no direction (scalar). Displacement is how far an object is from its starting point, in a straight line, including direction (vector).
In a 300 m race where the finish line is 100 m to the right of the start, what are the athletes' distance travelled and their displacement?
Distance travelled = 300 m. Displacement = 100 m to the right of the start.
Explain why mass is a scalar quantity but weight is a vector quantity.
Mass has magnitude only, so it is a scalar. Weight is a force with both magnitude and direction (due to gravity), so it is a vector.
If athletes run a full 400 m lap and return to their starting point, their total distance is 400 m but their ______ is zero.
If athletes run a full 400 m lap and return to their starting point, their total distance is 400 m but their displacement is zero.
True or False?
Speed and velocity are both scalar quantities.
False.
Speed is a scalar quantity, but velocity is a vector quantity because it also includes a direction.
Define speed.
Speed is the distance an object travels every second; it is a scalar quantity because it has magnitude only.
Write the equation used to calculate the speed of an object moving at constant speed.
$s p e e d = \frac{d i s t a n c e t r a v e l l e d}{t i m e t a k e n}$
How is the average speed of an object calculated?
$a v e r a g e s p e e d = \frac{t o t a l d i s t a n c e t r a v e l l e d}{t o t a l t i m e t a k e n}$
A plane flies at an average speed of 250 m/s for 2 hours. Calculate the total distance it travels.
Time = 2 × 60 × 60 = 7200 s. Distance = 250 × 7200 = 1 800 000 m.
When using a formula triangle, covering up the quantity you want to calculate is known as finding the ______ of the equation.
When using a formula triangle, covering up the quantity you want to calculate is known as finding the subject of the equation.
True or False?
Speed is a vector quantity.
False.
Speed is a scalar quantity because it only has magnitude, with no direction.
Define velocity.
Velocity is the speed of an object in a stated direction — a vector quantity, since it has both magnitude and direction.
What two pieces of information must be given to fully describe an object's velocity?
A magnitude (speed) and a direction, for example "15 m/s south" or "250 mph on a bearing of 030°".
Two cars travelling in different lanes at the same speed but in different directions have the same speed but different ______.
Two cars travelling in different lanes at the same speed but in different directions have the same speed but different velocities.
True or False?
Speed is a vector quantity.
False.
Speed is a scalar quantity; velocity is the vector quantity, since it also includes a direction.
A car's motion is described only as "15 m/s". Is this a speed or a velocity? Explain your answer.
This describes a speed, since only a magnitude is given. To describe a velocity, a direction would also need to be stated, for example "15 m/s south".
What does a distance-time graph show?
How the distance travelled by an object moving in a straight line changes over time.
What does a flat, horizontal line on a distance-time graph represent?
The object is stationary (not moving).
How can you tell whether an object is moving with a large or small speed from the slope of a straight line on a distance-time graph?
A steep slope represents a large speed; a shallow slope represents a small speed.
What does a curved line on a distance-time graph represent, and how do you tell if the object is speeding up or slowing down?
A curve represents a changing speed. An increasing slope means the object is speeding up; a decreasing slope means it is slowing down.
The speed of a moving object can be calculated from the ______ of the line on a distance-time graph.
The speed of a moving object can be calculated from the gradient of the line on a distance-time graph.
Write the equation used to calculate speed from the gradient of a distance-time graph.
$s p e e d = g r a d i e n t = \frac{Δ y}{Δ x}$ where Δy is the change in distance and Δx is the change in time.
True or False?
A straight, sloped line on a distance-time graph represents an object that is stationary.
False.
A straight, sloped line represents constant speed. Only a flat, horizontal line represents a stationary object.
A train travels 8 km in 6 minutes at a constant speed. Calculate its speed in m/s.
Distance = 8000 m, time = 360 s. Speed = 8000 ÷ 360 = 22.2 m/s.
Define acceleration.
Acceleration is the rate of change of velocity — how much an object's velocity changes every second.
Write the equation for acceleration, including the unit of each quantity.
$a = \frac{Δ v}{t}$ where a = acceleration (m/s²), Δv = change in velocity (m/s), t = time taken (s).
How is the change in velocity of an object calculated?
$Δ v = v - u$ — final velocity minus initial velocity.
True or False?
A negative value of acceleration means an object is speeding up.
False.
A negative acceleration (deceleration) means the object is slowing down; a positive acceleration means it is speeding up.
Define the acceleration due to gravity, g.
In the absence of air resistance, all objects near Earth's surface fall with the same acceleration, g = 10 m/s².
In freefall, with no air resistance, an object's velocity increases by ______ for every second it falls.
In freefall, with no air resistance, an object's velocity increases by 10 m/s for every second it falls.
Estimate the acceleration of a typical family car that speeds up from 0 m/s to 27 m/s in 10 seconds.
$a = \frac{27 - 0}{10} = 2.7 m / s^{2}$ — about 2.7 m/s².
Write the equation of motion used for uniformly accelerating objects when the time taken is not known.
$v^{2} - u^{2} = 2 a x$ where v = final speed, u = initial speed, a = acceleration, x = distance travelled.
State the units of each quantity in the equation $v^{2} - u^{2} = 2 a x$ .
u and v in metres per second (m/s); a in metres per second squared (m/s²); x in metres (m).
In the equation $v^{2} - u^{2} = 2 a x$ , the letter ______ represents the distance travelled, in metres.
In the equation $v^{2} - u^{2} = 2 a x$ , the letter x represents the distance travelled, in metres.
A car accelerates steadily from rest at 2.5 m/s² up to a speed of 16 m/s. Calculate the distance travelled during this acceleration.
$16^{2} - 0^{2} = 2 \times 2.5 \times x$ , so $256 = 5 x$ , giving x = 51.2 m.
True or False?
The equation $v^{2} - u^{2} = 2 a x$ can only be used if the time taken is known.
False.
This equation is useful precisely because it can be used when the time taken is not known.
Define velocity-time graph.
A velocity-time graph shows how the velocity of a moving object varies with time.
What does a straight line on a velocity-time graph represent?
A straight line represents constant acceleration (or deceleration); the slope of the line shows the magnitude of the acceleration.
How does the steepness of the slope on a velocity-time graph relate to the object's acceleration?
- A steep slope means a large acceleration (speed changes quickly)
- A gentle slope means a small acceleration (speed changes gradually)
- A flat line means zero acceleration (constant velocity)
On a velocity-time graph, a ______ line means the object is moving at a constant velocity.
On a velocity-time graph, a flat line means the object is moving at a constant velocity.
How can the acceleration of an object be calculated from a velocity-time graph?
By calculating the gradient of the line:
$a c c e l e r a t i o n = g r a d i e n t = \frac{Δ y}{Δ x}$
True or False?
A steep slope on a velocity-time graph means the object's speed changes slowly.
False.
A steep slope means a large acceleration, so speed changes quickly; a gentle slope means the speed changes gradually.
A cyclist's velocity-time graph gives a gradient triangle between 5 and 10 seconds, with a change in velocity of 5 m/s over a change in time of 5 s. Calculate the cyclist's acceleration.
$a = \frac{Δ y}{Δ x} = \frac{5}{5} = 1 {m s}^{- 2}$
What does the area under a velocity-time graph represent?
The displacement (or distance travelled) by the object.
How is the area under a velocity-time graph calculated when the enclosed shape is a triangle?
Area = ½ × base × height, used when the object is accelerating or decelerating.
How is the area under a velocity-time graph calculated when the enclosed shape is a rectangle?
Area = base × height, used when the object is moving at a constant velocity.
If a velocity-time graph consists of straight-line sections, the total distance travelled is found by adding the areas of the enclosed rectangles and ______.
If a velocity-time graph consists of straight-line sections, the total distance travelled is found by adding the areas of the enclosed rectangles and triangles.
A velocity-time graph shows a triangular section with a base of 40 s and a height of 17.5 m/s. Calculate the distance travelled during this section.
$A r e a = \frac{1}{2} \times 40 \times 17.5 = 350 m$
True or False?
The area under a velocity-time graph gives the acceleration of the object.
False.
The area gives the displacement (or distance travelled); the gradient gives the acceleration.
Define speed.
Speed is the distance travelled by an object every second: $s p e e d = \frac{d i s t a n c e}{t i m e}$
Name three factors that can affect a person's typical walking speed.
- Age
- Terrain
- Fitness
- Distance (length of the journey)
What piece of equipment is most appropriate for measuring a long distance, such as an athletics track?
A trundle wheel (or a long tape measure).
How does a single light gate measure the speed of an object passing through it?
A flag attached to the object blocks the light beam as it passes; the timer records how long the beam is blocked; the distance travelled is the length of the flag, so speed can be calculated from distance ÷ time.
A light gate can be used to ______ a timer when an object passes through it, using a flag to block the light beam.
A light gate can be used to start a timer when an object passes through it, using a flag to block the light beam.
True or False?
The typical walking speed of a person is about 6 m/s.
False.
The typical walking speed is about 1.5 m/s; 6 m/s would be far too fast for typical walking.
Name two factors that affect the typical speed of a transportation system, such as a car or plane.
- Shape
- Design
- Cost
- Purpose

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