Linear Motion

Question 1

Define linear motion

Answer 1

Motion in a curved or a straight line with all body parts moving at the same distance, at the same speed, and in the same direction

Question 2

What are the 10 measurements used in linear motion

Answer 2

Mass
Inertia
Distance
Speed
Weight
Acceleration
Deceleration
Displacement
Velocity
Momentum

Question 3

What is scalar described in terms of

Answer 3

Size OR magnitude

Question 4

What is vector described in terms of

Answer 4

Size AND direction

Question 5

What are the scalar measurements used in linear motion

Answer 5

Mass
Distance
Inertia
Speed

Question 6

What are the vector measurements used in linear motion

Answer 6

Weight
Acceleration
Deceleration
Displacement
Velocity
Momentum

Question 7

Define Newtons 1st law of motion

Answer 7

Every body continues in its rest or motion in a straight line unless compelled to change that state by external forces acting upon it

Question 8

What is inertia

Answer 8

The resistance an object has to change its state of motion

Question 9

Does it take more force to move something at rest or something already moving

Answer 9

If something is at rest it will take more force to get past rest and start moving than something already moving

Question 10

Define Newtons 2nd law of motion

Answer 10

The rate of change of momentum of a body (or the acceleration for a body of constant mass) is proportional to the force causing it and the change that takes place in the direction in which the force acts
The harder the force, the farther the object will go

Question 11

What 2 aspects does Newtons 2nd law relate to

Answer 11

Mass
Acceleration

Question 12

How can the size of the force in Newtons 2nd law be calculated

Answer 12

Using the equation
Net force = Mass x Acceleration
Fnet=MxA

Question 13

Define Newtons 3rd law of motion

Answer 13

To every action (force) there is an equal and opposite reaction (force)

Question 14

According to Newtons 3rd law, what is the relationship between the action force and the reaction force

Answer 14

The relationship is equal and opposite

Question 15

Define mass, is it scalar or vector? How do you know?

Answer 15

A physical quantity that identifies the amount of matter in a body, measured in Kgs
Scalar, it has no direction only a size

Question 16

Define weight and give its equation, is it scalar or vector? How do you know?

Answer 16

Weight is the force of a given weight due to gravity, measured in Newtons
Weight = Mass x Gravitational field strength —> gravitational force exerted on an object is directly proportional to mass
Vector, has a size and a direction

Question 17

Define displacement, is it scalar or vector? How do you know?

Answer 17

The length of a straight line from the start to the finish point
Vector, has a size and a direction

Question 18

Define distance, is it scalar or vector? How do you know?

Answer 18

The length of a path that a body follows when moving from one place to another
Scalar, no direction it only measures the size

Question 19

Define speed and give its equation, is it scalar or vector? How do you know?

Answer 19

Speed is the rate of change of position per time unit
Speed = Distance / Time
Scalar, it does not consider direction

Question 20

Define velocity, is it scalar or vector? How do you know?

Answer 20

The rate of change of displacement with reference to direction to give a more precise description of motion
Vector, it considers direction eg a car travels at 30 mph in an easterly direction

Question 21

Define acceleration and deceleration, are they scalar or vector? How do you know?

Answer 21

The rate of change of velocity
Acceleration = velocity increases Deceleration = velocity decreases
Vector, acceleration and deceleration involves velocity which involves direction

Question 22

Define momentum and give its equation, is it scalar or vector? How do you know?

Answer 22

The product of mass and velocity of an object, it is the amount of motion a body/object possesses
Momentum = Mass x Velocity
Vector, its calculated using velocity which considers both magnitude and direction, for example a mass which is able to move at a high velocity results in a high momentum

Question 23

Define centre of mass

Answer 23

The point of concentration of mass/balance of a body
Centre of mass constantly changes as we move

Question 24

Where is the centre of mass usually situated

Answer 24

At the hips

Question 25

How does the centre of mass differ for males and females? Why?

Answer 25

Male centre of mass is generally higher than females
This is because males have more mass in their upper body, generally concentrated around their shoulders

Question 26

How can centre of mass change as we move? Why is this important

Answer 26

Raising your arms above your head raises your centre of mass
This allows your body to remain balanced

Question 27

What are the 4 factors affecting stability

Answer 27

Height of centre of mass
Mass of performer
Area of support base
Position of the line of gravity

Question 28

How can the height of the centre of mass affect the stability of a performer

Answer 28

The lower the COM the higher the level of stability

Question 29

How can the mass of the performer affect the stability of a performer

Answer 29

The greater the mass, the more stability

Question 30

How can the area of base of support affect the stability of a performer

Answer 30

The more contact points with the floor, the more stability the performer will have

Question 31

How can the position of line of gravity affect the stability of a performer

Answer 31

If the line of gravity is central over the base of support, the stability is increased