Define scalar quantity .

A scalar quantity has magnitude only, with no direction.

Define vector quantity .

A vector quantity has both magnitude and direction .

What is the difference between distance and displacement ?

Distance is the total length of the path travelled, regardless of direction, so it is a scalar quantity. Displacement is the length and direction of a straight line from the starting point to the finishing point, so it is a vector quantity.

What is the difference between speed and velocity ?

Speed is the distance travelled per unit time, regardless of direction, so it is a scalar quantity. Velocity is the displacement per unit time, including direction, so it is a vector quantity.

Mass is a scalar quantity, but weight is a .......... quantity because it has both magnitude and direction.

Mass is a scalar quantity, but weight is a vector quantity because it has both magnitude and direction.

True or False? An object moving at a constant speed can have a changing velocity.

True. Velocity depends on both speed and direction, so if the object changes direction while travelling at a constant speed, its velocity still changes.

Give two examples of scalar quantities and two examples of vector quantities.

Examples of scalar quantities include distance, speed, mass, time, energy, volume, density, pressure, electric charge and temperature. Examples of vector quantities include displacement, velocity, acceleration, force and momentum.

Define resultant vector .

The single vector produced by adding or subtracting two or more vectors; also known as the net vector.

How is the magnitude of the resultant of two perpendicular vectors calculated?

Using Pythagoras' theorem , since the two vectors form a right-angled triangle.

How is the direction of a resultant vector found, once its magnitude has been calculated?

Using trigonometry (sine, cosine or tangent) to calculate the angle from the horizontal or vertical.

Name the two methods used to combine vectors that are not at right angles.

The triangle method and the parallelogram method .

To combine vectors using the triangle method, the vectors are linked .......... , then the resultant vector connects the tail of the first vector to the head of the second.

To combine vectors using the triangle method, the vectors are linked head-to-tail , then the resultant vector connects the tail of the first vector to the head of the second.

Under what conditions is an object considered to be in equilibrium?

When it is at rest or moving at constant velocity .

True or False? An object can only be in equilibrium if it is stationary.

False. An object is in equilibrium if it is at rest or moving at constant velocity , not stationary only.

List four forces commonly represented in a vector triangle for an object in equilibrium.

Weight , normal reaction force , tension and friction .

Define components (of a vector).

The two vectors that a resultant vector is split into, which together have the same effect as the original vector.

On an inclined plane, it is easier to resolve forces into components .......... and perpendicular to the slope, rather than horizontal and vertical.

On an inclined plane, it is easier to resolve forces into components parallel and perpendicular to the slope, rather than horizontal and vertical.

On a frictionless inclined plane at angle θ , which force component causes the object to slide down the slope?

The component of weight parallel to the slope, W sin θ .

On an inclined plane, why does the normal force R equal W cos θ ?

Because the object does not move perpendicular to the slope, so R balances the perpendicular component of weight.

True or False? The vertical component of a force F at angle θ to the horizontal is F cos θ .

False. The vertical component is F sin θ ; F cos θ is the horizontal component.

A LevelPhysicsOCRFlashcards2. Foundations in PhysicsScalars & Vectors

Scalars & Vectors (OCR A Level Physics): Flashcards

Exam code: H556

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Define scalar quantity.

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Cards in this collection (22)

Define scalar quantity.
A scalar quantity has magnitude only, with no direction.
Define vector quantity.
A vector quantity has both magnitude and direction.
What is the difference between distance and displacement?
Distance is the total length of the path travelled, regardless of direction, so it is a scalar quantity. Displacement is the length and direction of a straight line from the starting point to the finishing point, so it is a vector quantity.
What is the difference between speed and velocity?
Speed is the distance travelled per unit time, regardless of direction, so it is a scalar quantity. Velocity is the displacement per unit time, including direction, so it is a vector quantity.
Mass is a scalar quantity, but weight is a .......... quantity because it has both magnitude and direction.
Mass is a scalar quantity, but weight is a vector quantity because it has both magnitude and direction.
True or False?
An object moving at a constant speed can have a changing velocity.
True.
Velocity depends on both speed and direction, so if the object changes direction while travelling at a constant speed, its velocity still changes.
Give two examples of scalar quantities and two examples of vector quantities.
Examples of scalar quantities include distance, speed, mass, time, energy, volume, density, pressure, electric charge and temperature. Examples of vector quantities include displacement, velocity, acceleration, force and momentum.
Define resultant vector.
The single vector produced by adding or subtracting two or more vectors; also known as the net vector.
How is the magnitude of the resultant of two perpendicular vectors calculated?
Using Pythagoras' theorem, since the two vectors form a right-angled triangle.
How is the direction of a resultant vector found, once its magnitude has been calculated?
Using trigonometry (sine, cosine or tangent) to calculate the angle from the horizontal or vertical.
Name the two methods used to combine vectors that are not at right angles.
The triangle method and the parallelogram method.
To combine vectors using the triangle method, the vectors are linked .........., then the resultant vector connects the tail of the first vector to the head of the second.
To combine vectors using the triangle method, the vectors are linked head-to-tail, then the resultant vector connects the tail of the first vector to the head of the second.
Under what conditions is an object considered to be in equilibrium?
When it is at rest or moving at constant velocity.
True or False?
An object can only be in equilibrium if it is stationary.
False.
An object is in equilibrium if it is at rest or moving at constant velocity, not stationary only.
List four forces commonly represented in a vector triangle for an object in equilibrium.
Weight, normal reaction force, tension and friction.
Define components (of a vector).
The two vectors that a resultant vector is split into, which together have the same effect as the original vector.
For a force F at angle θ to the horizontal, what is its horizontal component?
$F_{x} = F \cos θ$
For a force F at angle θ to the horizontal, what is its vertical component?
$F_{y} = F \sin θ$
On an inclined plane, it is easier to resolve forces into components .......... and perpendicular to the slope, rather than horizontal and vertical.
On an inclined plane, it is easier to resolve forces into components parallel and perpendicular to the slope, rather than horizontal and vertical.
On a frictionless inclined plane at angle θ, which force component causes the object to slide down the slope?
The component of weight parallel to the slope, W sin θ.
On an inclined plane, why does the normal force R equal W cos θ?
Because the object does not move perpendicular to the slope, so R balances the perpendicular component of weight.
True or False?
The vertical component of a force F at angle θ to the horizontal is F cos θ.
False.
The vertical component is F sin θ; F cos θ is the horizontal component.

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