Biomechanical Principles, Levers And Use Of Technology✅ Flashcards
What is Newton’s first law (definition)
Law of inertia: a body continues in a state or rest or uniform velocity unless acted upon by an external or unbalanced force
What is Newton’s second law (definition)
Law of acceleration: a body’s rate of change of momentum is proportional to the size of the force applied and acts in the same direction as the force applied
What is Newton’s third law (definition)
Law of reaction: for every action there is an equal and opposite reaction
Give an application for Newton’s first law
Law of inertia: golf ball remains still unless force applied by a golf club makes it move, or golf ball continue to move at constant velocity unless a force acts on it to slow it down (eg wind resistance)
Give an application for Newton’s second law
Law of acceleration: golf ball struck by golf club, the rage of change of momentum (or velocity) of ball is proportional to size of force applied to it by club. The bigger the forge the greater the acceleration
Give an application of Newton’s third law
Law of reaction: if a tennis plays hits a ball, the racquet exerts a force on the ball and the ball exerts an equal and opposite force on the racquet, the racquet exerts the action force and the ball exerts the reaction force
What is the definition and equation for velocity
M/s
Rate of change of displacement (shortest straight line route between start and finish)
Velocity= displacement/time taken
What is the definition of momentum and the equation
kgm/s
Quantity of motion possessed by a moving body
Momentum=mass X velocity
What is the definition and equation for acceleration
M/s/s
Rate of change in velocity
Acceleration= (final velocity-initial velocity)/ time taken
What is the definition and equation for force
N
A push or a pull that alters the state of motion of a body
Force= mass X acceleration
What are internal and external forces
Internal: generated by skeletal muscles
External: comes from outside the body
What 5 effects can force have
Create motion
Accelerate a body
Decelerate a body
Change the direction of a body
Change the shape of a body
If net force is 0 what happens, if a net force is present what happens
No change in motion as forces are balanced
Change in motion as forces are unbalanced, occurs when 2 forces are unequal in size and opposite in direction
What are the vertical and horizontal forces in external forces
Vertical: weight (gravitational pull that earth exerts on a body) and reaction (equal and opposite force placed upon it)
Horizontal: friction (force that opposes the motion of two surfaces in contact) and air resistance (force that opposes motion through the air)
What factors affect friction, give example for each one
Roughness of ground surface (athletes run on rough, rubberized tracks)
Roughness of contact surface (athletes wear spiked shoes)
Temperature (F1 drivers warm up tires)
Size of normal reaction (shot putters have high mass, Newton’s third law, allowing grater friction in the throwing circle and preventing over-rotation
What factors affect air resistance, give example for each one
Velocity (greater the velocity of a cyclist, the greater the force of air resistance opposing their motion)
Shape, (most cyclists wear helmet with tear drop or aero foil shape, streamline)
Frontal cross-sectional area, (the low crouched position of a downhill skier reduces air resistance)
Smoothness of surface, (increased smoothness from Lycra suits reduces air resistance)
How do you draw a free body diagram
W (from CoM) and R (from point of contact) as vertical forces
F (from point of contact) and AR (from CoM) as horizontal forces
Include direction of motion and correct length of arrows to show relative proportions
What is the centre of mass
The point at which an object or a body is balanced in all directions; the point at which weight appears to act
What factors affect stability
Mass of body: greater the mass, the greater the inertia
Height of centre of mass: the lower the CoM, the greater the stability
Base of support: the greater the size of the base of support, the greater the stability, this can be increased by more points of contact
Line of gravity: the more central the line of gravity to the base of support, the greater the stability
When would you want to maximize and minimize stability for a sprinter
Maximize stability in the blocks (low CoM, large base of support, line of gravity in line with CoM, low height of CoM)
Minimize stability to aid performance (chest lifts, raising CoM; hands come off track, reducing base and contacts of support; line of gravity falls infront of body, causing the body to fall forwards)
What is a first class lever, give an example
Fulcrum is in the middle
Extension of neck when preparing to head a football (E-F-L)
What is a second class lever, give an example
Load is in the middle Extension of
Ball of the foot in the take-off phase of a high jump (E-L-F)
What is a third class lever, give an example
Effort is in the middle
Flexion of the elbow during a biceps curl (L-E-F)
How to maximize efficiency of a lever
The smaller the distance of the effort or load from the fulcrum the less significant the effort or load becomes
Longer levers generate greater forces as the load as load arm becomes longer and therefore can give greater acceleration to projectiles
Give an example of a mechanical advantage
Second class lever has advantage to move large load with small effort, such as at ball of foot to vertically accelerate an atheletes whole weight easily
Give an example of a mechanical disadvantage
Third class lever has disadvantage, requiring large effort to move relatively small load eg flexion of elbow in upwards phase of bicep curl
Give definition and use of limb kinematics and optimizing performance
Study of movement in relation to time and space
3D or optical motion analysis records an athlete performing a sporting action, allowing evaluation of efficiency of movement
Data producer can be used by coaches to improve performance/specific techniques of athletes
Give definition, use and how to optimize performance for force plates
Ground reaction forces are measured in laboratory conditions using force plates
Athletes balance, run and jump on force plates, which access sixe and direction or force, acceleration rates, work and power output
Used for sports biomechanics, physical therapy, balance rehabilitation, gait analysis
Give definition, use and how to optimize performance for wind tunnels
Steel frame building containing wide fans, where artificial wind is produced
Technology used to develop DRS, objects such as cycle helmet L’s and F1 cars can be tested for aerodynamic efficiency
Engineers study flow of air around an object, aim to improve flow of air around an object, making more streamline, increasing lift or reducing drag
