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

A scalar quantity has only magnitude and no direction, for example mass .

What is the difference between distance and displacement ?

Distance is a scalar measuring the length of the path travelled. Displacement is a vector measuring the length and direction of a straight line from the start point to the end point.

Name three pairs of commonly confused scalar and vector quantities.

Distance and displacement ; speed and velocity ; weight and mass .

How is a vector represented on a diagram?

As an arrow . The length of the arrow represents the magnitude of the vector, and the direction of the arrow represents its direction .

A car travelling at 60 km per hour in a Westerly direction is describing its ______ .

A car travelling at 60 km per hour in a Westerly direction is describing its velocity .

True or False? Displacement is a scalar quantity.

False. Displacement is a vector quantity because it describes both the distance and the direction between two points, unlike distance , which is a scalar.

A force is a push or a pull that acts on an object due to the interaction with another object.

What are the three ways a force can affect an object?

A force can change an object's speed , direction , or shape .

Define contact force .

A contact force is a force which acts between objects that are physically touching .

Define non-contact force .

A non-contact force is a force which acts at a distance , without any contact between bodies, due to the action of a field .

Name four examples of contact forces.

Friction , air resistance , tension and normal contact force .

Name three examples of non-contact forces.

Gravitational force , electrostatic force and magnetic force .

Friction is a force that opposes ______ and occurs when objects rub against each other.

Friction is a force that opposes motion and occurs when objects rub against each other.

True or False? Air resistance is a non-contact force.

False. Air resistance is a type of friction , and friction is a contact force .

A force pair occurs when an interaction between two objects results in a force being exerted on each object by the other .

How can the direction of a force be described?

As left , right , up , down , or using an angle described with respect to the vertical or the horizontal.

On a number line representing force direction, what do positive and negative values represent?

Numbers to the right of zero are positive, matching forces pointing right . Numbers to the left of zero are negative, matching forces pointing left .

Describe the force pair acting between a laptop resting on a desk.

The laptop exerts a downward force on the desk , and the desk exerts an upward force on the laptop .

Describe the force pair acting between a person standing on the Earth.

The Earth exerts a gravitational pull force on the person , and the person exerts a gravitational pull force on the Earth .

Forces are vector quantities as they are described by both magnitude and ______ .

Forces are vector quantities as they are described by both magnitude and direction .

True or False? A basketball player throwing a ball experiences no force from the ball.

False. This is a force pair — the basketball player exerts a push force on the ball , and the ball exerts a push force back on the basketball player .

Weight is the force acting on an object due to gravitational attraction .

Mass is related to the amount of matter in an object, measured in kilograms (kg).

What instrument measures mass, and what instrument measures weight directly?

Mass is measured using a top pan balance . Weight is measured directly using a newtonmeter (a calibrated spring-balance).

Define centre of mass .

The centre of mass is the point through which the weight of an object acts.

Where is the centre of mass located for a symmetrical object of uniform density?

At the object's point of symmetry , for example the centre of a sphere.

How can the centre of mass of an irregular object be found?

By locating its balance point .

Since weight is a force, it is measured in ______ .

Since weight is a force, it is measured in newtons (N) .

True or False? Mass and weight are the same thing.

False. Mass is the amount of matter in an object, measured in kg, while weight is the force due to gravitational attraction acting on that mass, measured in N.

g is known as the acceleration due to gravity or the gravitational field strength .

An object in free fall is falling solely under the influence of gravity .

What happens to an object's mass and weight when it moves from Earth to a planet with a different gravitational field strength?

Its mass stays the same, but its weight changes, since weight depends on the gravitational field strength.

Why is weight a vector quantity while mass is a scalar quantity?

Weight is a force, with both magnitude and direction, so it is a vector. Mass has magnitude but no direction, so it is a scalar.

The gravitational field strength on the Moon is 1.63 N/kg. How does an object's weight on the Moon compare to its weight on Earth?

It is about six times less than its weight on Earth.

True or False? On Earth, all free-falling objects accelerate towards Earth at a rate of 9.8 m/s².

True. On Earth, all free-falling objects accelerate towards Earth at a rate of 9.8 m/s² .

True or False? Weight and mass are directly proportional.

True. The weight of an object and its mass are directly proportional , with the size of the weight force depending on the gravitational field strength .

Define resultant force .

A resultant force is a single force that describes the combined effect of all the forces acting on a body; also called the net force .

Define balanced forces .

Balanced forces combine in such a way that they cancel each other out, meaning there is no resultant force on the body.

Define unbalanced forces .

Unbalanced forces do not cancel out completely, resulting in a resultant force acting on the object.

How do you combine forces acting in the same direction, and forces acting in opposite directions, to find the resultant force?

Forces acting in the same direction are added together. Forces acting in opposite directions are subtracted from each other.

When stating a resultant force as your final answer, what two things must you always include?

The magnitude and the direction of the resultant force.

Two people play tug-of-war: person A pulls 80 N to the left and person B pulls 100 N to the right. What is the resultant force?

A resultant force of 20 N to the right , since the forces do not cancel out completely.

The weight of a book on a desk is balanced by the ______ force of the desk.

The weight of a book on a desk is balanced by the normal force of the desk.

True or False? In a diagram with 14 N to the left, 4 N to the right and 8 N to the right, the resultant force is 2 N to the right.

False. Adding the rightward forces gives 12 N (4 N + 8 N), which is less than the 14 N to the left, so the resultant force is 2 N to the left .

Tension is the force experienced by a cable, rope, or string when pulled, hung, rotated or supported. It always acts away from the mass and is labelled T on free body diagrams.

Define normal contact force .

The normal contact force is the force arising when an object rests against another object, acting at 90° to the plane of contact. It arises from Newton's third law and is labelled N or R on free body diagrams.

Upthrust is the upward buoyancy force acting on an object when it is in a fluid.

Friction is the force that arises when two surfaces are in contact with each other. It always opposes the motion and is labelled F or Fr on free body diagrams.

What is a free body diagram used for?

A free body diagram is used to model the forces acting on an object. It can be used to identify which forces act in which plane, and to resolve the net force in a particular direction.

How is each force represented on a free body diagram ?

Each force is represented as a vector arrow that is scaled to the magnitude of the force, points in the direction the force acts, and is labelled with the name of the force.

GCSEPhysicsAQAFlashcardsForcesForces & their Interactions

Forces & their Interactions (AQA GCSE Physics): Flashcards

Exam code: 8463

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Cards in this collection (62)

Define vector.
A vector quantity has both magnitude and direction, for example velocity.
Define scalar.
A scalar quantity has only magnitude and no direction, for example mass.
What is the difference between distance and displacement?
Distance is a scalar measuring the length of the path travelled. Displacement is a vector measuring the length and direction of a straight line from the start point to the end point.
Name three pairs of commonly confused scalar and vector quantities.
Distance and displacement; speed and velocity; weight and mass.
How is a vector represented on a diagram?
As an arrow. The length of the arrow represents the magnitude of the vector, and the direction of the arrow represents its direction.
A car travelling at 60 km per hour in a Westerly direction is describing its ______.
A car travelling at 60 km per hour in a Westerly direction is describing its velocity.
True or False?
Displacement is a scalar quantity.
False.
Displacement is a vector quantity because it describes both the distance and the direction between two points, unlike distance, which is a scalar.
Define force.
A force is a push or a pull that acts on an object due to the interaction with another object.
What are the three ways a force can affect an object?
A force can change an object's speed, direction, or shape.
Define contact force.
A contact force is a force which acts between objects that are physically touching.
Define non-contact force.
A non-contact force is a force which acts at a distance, without any contact between bodies, due to the action of a field.
Name four examples of contact forces.
Friction, air resistance, tension and normal contact force.
Name three examples of non-contact forces.
Gravitational force, electrostatic force and magnetic force.
Friction is a force that opposes ______ and occurs when objects rub against each other.
Friction is a force that opposes motion and occurs when objects rub against each other.
True or False?
Air resistance is a non-contact force.
False.
Air resistance is a type of friction, and friction is a contact force.
Define force pair.
A force pair occurs when an interaction between two objects results in a force being exerted on each object by the other.
How can the direction of a force be described?
As left, right, up, down, or using an angle described with respect to the vertical or the horizontal.
On a number line representing force direction, what do positive and negative values represent?
Numbers to the right of zero are positive, matching forces pointing right. Numbers to the left of zero are negative, matching forces pointing left.
Describe the force pair acting between a laptop resting on a desk.
The laptop exerts a downward force on the desk, and the desk exerts an upward force on the laptop.
Describe the force pair acting between a person standing on the Earth.
The Earth exerts a gravitational pull force on the person, and the person exerts a gravitational pull force on the Earth.
Forces are vector quantities as they are described by both magnitude and ______.
Forces are vector quantities as they are described by both magnitude and direction.
True or False?
A basketball player throwing a ball experiences no force from the ball.
False.
This is a force pair — the basketball player exerts a push force on the ball, and the ball exerts a push force back on the basketball player.
Define weight.
Weight is the force acting on an object due to gravitational attraction.
Define mass.
Mass is related to the amount of matter in an object, measured in kilograms (kg).
What instrument measures mass, and what instrument measures weight directly?
Mass is measured using a top pan balance. Weight is measured directly using a newtonmeter (a calibrated spring-balance).
Define centre of mass.
The centre of mass is the point through which the weight of an object acts.
Where is the centre of mass located for a symmetrical object of uniform density?
At the object's point of symmetry, for example the centre of a sphere.
How can the centre of mass of an irregular object be found?
By locating its balance point.
Since weight is a force, it is measured in ______.
Since weight is a force, it is measured in newtons (N).
True or False?
Mass and weight are the same thing.
False.
Mass is the amount of matter in an object, measured in kg, while weight is the force due to gravitational attraction acting on that mass, measured in N.
Define g.
g is known as the acceleration due to gravity or the gravitational field strength.
State the equation linking weight, mass and gravitational field strength.
$W = m g$
Define free fall.
An object in free fall is falling solely under the influence of gravity.
What happens to an object's mass and weight when it moves from Earth to a planet with a different gravitational field strength?
Its mass stays the same, but its weight changes, since weight depends on the gravitational field strength.
Why is weight a vector quantity while mass is a scalar quantity?
Weight is a force, with both magnitude and direction, so it is a vector. Mass has magnitude but no direction, so it is a scalar.
The gravitational field strength on the Moon is 1.63 N/kg. How does an object's weight on the Moon compare to its weight on Earth?
It is about six times less than its weight on Earth.
True or False?
On Earth, all free-falling objects accelerate towards Earth at a rate of 9.8 m/s².
True.
On Earth, all free-falling objects accelerate towards Earth at a rate of 9.8 m/s².
True or False?
Weight and mass are directly proportional.
True.
The weight of an object and its mass are directly proportional, with the size of the weight force depending on the gravitational field strength.
Define resultant force.
A resultant force is a single force that describes the combined effect of all the forces acting on a body; also called the net force.
Define balanced forces.
Balanced forces combine in such a way that they cancel each other out, meaning there is no resultant force on the body.
Define unbalanced forces.
Unbalanced forces do not cancel out completely, resulting in a resultant force acting on the object.
How do you combine forces acting in the same direction, and forces acting in opposite directions, to find the resultant force?
Forces acting in the same direction are added together. Forces acting in opposite directions are subtracted from each other.
When stating a resultant force as your final answer, what two things must you always include?
The magnitude and the direction of the resultant force.
Two people play tug-of-war: person A pulls 80 N to the left and person B pulls 100 N to the right. What is the resultant force?
A resultant force of 20 N to the right, since the forces do not cancel out completely.
The weight of a book on a desk is balanced by the ______ force of the desk.
The weight of a book on a desk is balanced by the normal force of the desk.
True or False?
In a diagram with 14 N to the left, 4 N to the right and 8 N to the right, the resultant force is 2 N to the right.
False.
Adding the rightward forces gives 12 N (4 N + 8 N), which is less than the 14 N to the left, so the resultant force is 2 N to the left.
Define tension.
Tension is the force experienced by a cable, rope, or string when pulled, hung, rotated or supported. It always acts away from the mass and is labelled T on free body diagrams.
Define normal contact force.
The normal contact force is the force arising when an object rests against another object, acting at 90° to the plane of contact. It arises from Newton's third law and is labelled N or R on free body diagrams.
Define upthrust.
Upthrust is the upward buoyancy force acting on an object when it is in a fluid.
Define friction.
Friction is the force that arises when two surfaces are in contact with each other. It always opposes the motion and is labelled F or Fr on free body diagrams.
What is a free body diagram used for?
A free body diagram is used to model the forces acting on an object. It can be used to identify which forces act in which plane, and to resolve the net force in a particular direction.
How is each force represented on a free body diagram?
Each force is represented as a vector arrow that is scaled to the magnitude of the force, points in the direction the force acts, and is labelled with the name of the force.
Each force on a free body diagram is represented as a vector arrow that is scaled to the ______ of the force it represents.
Each force on a free body diagram is represented as a vector arrow that is scaled to the magnitude of the force it represents.
True or False?
Upthrust can only act on an object if it is in a liquid.
False.
Upthrust can occur in both liquids and gases.
Define balanced forces.
Balanced forces are forces acting on an object where there is no resultant force.
Define unbalanced forces.
Unbalanced forces are forces acting on an object where there is a resultant force.
What does it mean if force vector arrows form a closed loop when added together?
The forces are balanced - there is no resultant force.
A single force acting at an angle can be resolved into two components: a horizontal component and a ______ component.
A single force acting at an angle can be resolved into two components: a horizontal component and a vertical component.
Why might a force acting at an angle be resolved?
So that it can be broken down into a horizontal component and a vertical component, making the force easier to analyse.
True or False?
When combining force vectors to find a resultant, the arrows are placed head-to-head.
False.
The arrows are placed head to tail, with the resultant vector starting at the tail of the first vector and ending at the head of the second.
What are the two methods used to combine vectors using a scale diagram?
The triangle method and the parallelogram method.
In the parallelogram method, how is the magnitude of the resultant vector found?
The resultant vector is the diagonal of the parallelogram. Its magnitude is found by measuring the length of this diagonal and converting it using the scale used.

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