3.1 Newton's laws of motion, force and the use of technology Flashcards
What is Newton’s First Law
Law of Inertia
What does Newton’s First Law state
states that object will remain at rest/ in uniform motion in a straight line unless acted upon by an external force
What is Newton’s Second Law
Law of acceleration
What does Newton’s Second Law state
the acceleration of body is proportional to force causing it -> acceleration takes place in direction force ends
What is Newton’s Third Law
Law of Motion
What does Newton’s Third Law state
when one object exerts a force on a second object, there is equal and opposite force exerted by second object on the first
What is the formula for velocity
velocity = displacement/ time taken
What is the formula for momentum
momentum = mass x velocity
What is the formula for acceleration
acceleration = (final velocity - initial velocity) / time taken
What is the formula for force
force = mass x acceleration
What is a force
A push or a pull that tends to alter the state of motion of a body
Name the 2 types of force
Internal and external force
What is internal force
-generated by contraction of skeletal muscle
Give an example of an internal force
100m - contract rectus femoris - extend knee - drive away from the blocks
What is an external force
comes from OUTSIDE the body and acts upon it
What are the 5 effects of FORCE ?
- create motion
- accelerate a body
- decelerate a body
- changing the direction
- changing the shape
What is net force
the sum of all forces acting on a body
what is a balanced force
when two or more forces acting on a body are equal in size and opposite in direction
-net force = 0
-body will remain at rest/ in motion eith constant velocity
what is an unbalanced force
when 2 forces are unequal in size & opposite in direction
-net force present
body changes state of motion- accelerating/ decelerating
Name the 2 vertical forces
-weight
-reaction
What is weight and what is it measured in
the gravitational pull the earth exerts on a body
-always present and acts downwards from bodys centre of mass
-measured in newtons
Give the formula for how weight is calcukated
weight (N) = mass x acceleration due to gravity
What is reaction and what is it measured in
equal and opposite force exerted by body in response to action force placed upon it
-always present when two bodies are in contact
-measured in Newtons
Name the 2 horzionatl forces
-friction
-air resistance
What is air resistance
force that opposes motion of a body travelling through the air
Name 4 factors that affect air resistance
-velocity- increasing velocity increases air resistance
-shape- more aerodynmaic the shape, the lower the air resistance
-frontal cross- decreasing frontal cross, decreases air resistance
-smoothness of surface- improving smoothness of surface decreases air resistance
Where does friction act from
point of contact
What is the centre of mass
the point at which a body is balanced in all directions
What is stability
The ability of a body to resist motion and remain at rest
What 4 factors effect stability
-mass of body- greater mass, greater the inertia, greater the stability
-height of centre of mass- lower centre of mass, greater stability
-base of support- greater size of base of support, greater the stability
-line of gravity- more centra line of gravity to base of support, greater the stability
How does the fosbury flop use centre of mass
- uses j curve to allow greater velocity
- plants outside leg to allow inside leg to lift, along with arms, at take off to raise the centre of mass as high as possible
- fully extends spine to rotate around the bar moving the centre of mass outside of the body and below the bar. Only one section of body has to be above the bar at one time.
( centre of mass passes underneath the bar, fosbury flop requires less take off force to clear the same height as earlier techniques . when maximum force is generated at take-off greater heights can be achieved.)
What is linear motion
straight line
What is angular motion
rotation about a particular point (axis of rotation)
Give an example of how you can maximise stability
-a sprinter crouching down in the blocks
-this gives low centre of mass
-base of support is large
-5 points of contact (two feet, two hands, one knee)
Give an example of how you minimise stability
-when ‘set’ is called- sprinter lifts hips- raising centre of mass
-lifts one knee reducing points of contact
-leans forward shifting line of stability
What are lever systems
the co-ordination of our bones and muscles, primarily to create human movement
Name the two main functions of lever systems
- to generate muscular effort to overcome a given load
- to increase the speed of a given movement
What are the 4 component parts of a lever system
- lever
-fulcrum - effort
- load
Give an example of a lever
a bone
Give an example of a fulcrum
a joint
Name the three types of lever system
-first-class levers
-second-class levers
-third-class levers
Name the component order of first-class levers
-effort and load either side of fulcrum in middle
-E—–F—–L
Name the component order of second-class levers
-effort and fulcrum either side of the load in middle
-E——L——F
Name the component order of third-class levers
-load and fulcrum either side of effort in the middle
-L——-E——-F
Give an example of first class levers in the body
extension of neck when preparing to head a football
Give an example of second class levers in the body
ball of foot in take-off phase of a high-jump
Give an example of third class levers in the body
flexion of elbow during bicep curl
What is the distance from the fulcrum to the effort known as
effort arm
What is the distance from the load to the fulcrum known as
load arm
The greater the distance of the effort or load from the fulcrum …
the more significant the effort or load becomes
What is a mechanical advantage
second class lever systems where the effort arm is greater than the load arm. a large load can be moved with a relatively small effort
What is a mechanical disadvantage
third class lever systems where the load arm is greater than the effort arm. a large effort is required to move a relatively small load
Name 3 types of technology you could use to analyse movement
-limb kinetics
-force plates
-wind tunnels
What is limb kinetics
study of movement in relation to time and space
-3D records athlete peforming sporting action
-it analyses efficiency of movement
-this datas used to better performers technique
What are force plates
measure ground reaction forces
-athletes balance, run, jump on force plates -> tells them size & direction of forces acting on athlete
-used for sports biomechanics assessment
What are wind tunnels
-steel frame building, have wide fans -> producing artificial wind
-used to develop drag reduction system
