Linear Motion Flashcards
Define linear motion
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
What are the 10 measurements used in linear motion
Mass
Inertia
Distance
Speed
Weight
Acceleration
Deceleration
Displacement
Velocity
Momentum
What is scalar described in terms of
Size OR magnitude
What is vector described in terms of
Size AND direction
What are the scalar measurements used in linear motion
Mass
Distance
Inertia
Speed
What are the vector measurements used in linear motion
Weight
Acceleration
Deceleration
Displacement
Velocity
Momentum
Define Newtons 1st law of motion
Every body continues in its rest or motion in a straight line unless compelled to change that state by external forces acting upon it
What is inertia
The resistance an object has to change its state of motion
Does it take more force to move something at rest or something already moving
If something is at rest it will take more force to get past rest and start moving than something already moving
Define Newtons 2nd law of motion
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
What 2 aspects does Newtons 2nd law relate to
Mass
Acceleration
How can the size of the force in Newtons 2nd law be calculated
Using the equation
Net force = Mass x Acceleration
Fnet=MxA
Define Newtons 3rd law of motion
To every action (force) there is an equal and opposite reaction (force)
According to Newtons 3rd law, what is the relationship between the action force and the reaction force
The relationship is equal and opposite
Define mass, is it scalar or vector? How do you know?
A physical quantity that identifies the amount of matter in a body, measured in Kgs
Scalar, it has no direction only a size
Define weight and give its equation, is it scalar or vector? How do you know?
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
Define displacement, is it scalar or vector? How do you know?
The length of a straight line from the start to the finish point
Vector, has a size and a direction
Define distance, is it scalar or vector? How do you know?
The length of a path that a body follows when moving from one place to another
Scalar, no direction it only measures the size
Define speed and give its equation, is it scalar or vector? How do you know?
Speed is the rate of change of position per time unit
Speed = Distance / Time
Scalar, it does not consider direction
Define velocity, is it scalar or vector? How do you know?
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
Define acceleration and deceleration, are they scalar or vector? How do you know?
The rate of change of velocity
Acceleration = velocity increases Deceleration = velocity decreases
Vector, acceleration and deceleration involves velocity which involves direction
Define momentum and give its equation, is it scalar or vector? How do you know?
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
Define centre of mass
The point of concentration of mass/balance of a body
Centre of mass constantly changes as we move
Where is the centre of mass usually situated
At the hips
How does the centre of mass differ for males and females? Why?
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
How can centre of mass change as we move? Why is this important
Raising your arms above your head raises your centre of mass
This allows your body to remain balanced
What are the 4 factors affecting stability
Height of centre of mass
Mass of performer
Area of support base
Position of the line of gravity
How can the height of the centre of mass affect the stability of a performer
The lower the COM the higher the level of stability
How can the mass of the performer affect the stability of a performer
The greater the mass, the more stability
How can the area of base of support affect the stability of a performer
The more contact points with the floor, the more stability the performer will have
How can the position of line of gravity affect the stability of a performer
If the line of gravity is central over the base of support, the stability is increased
