Biomechanical movement (P2) Flashcards
What is a scalar quantity?
When measurements are only described in terms of size/magnitude- mass, distance and speed.
What is a vector quantity?
When measurements are described in terms of magnitude and direction- weight, acceleration, displacement, velocity and momentum.
In terms of vectors, what does an arrow show?
The magnitude and direction
What is mass?
The quantity of matter the body possess. Measured in kg
What is weight?
The gravitational force exerted on an object. Measured in Newtons
What is distance?
The path a body takes as it moves from the starting to the finishing position. Measured in metres.
What is displacement?
The shortest route in a straight line between the starting and finishing position.
What is speed?
The rate of change over a distance. Measured in m/s.
What is velocity?
The rate of change of displacement. Measure in metres per second.
What is the formula for speed?
Distance covered (m)/time taken (s)= speed (m/s)
What is the formula for velocity?
Displacement (m)/ time taken (s)=velocity (m/s)
What does a distance-time graph show?
The distance travelled over a period of time.
How do you work out the gradient of a graph?
Changes in y-axis/ changes in x-axis
What do velocity-time graphs and speed-time graphs show?
Indicates the velocity or speed of a performer or object per unit of time.
What is acceleration?
The rate of change of velocity. Measured in m/s^2
What is the formula for acceleration?
Change in velocity (m/s)/ time (s)= acceleration (m/s^2)
What is momentum?
The product of the mass and velocity of an object. Measured in (kgm/s).
What is the formula for momentum?
Mass (kg) x velocity (m/s)= momentum (kgm/s)
What are the two types of force?
Internal and external
What is an internal force?
A force generated from the contraction of the skeletal muscles
What is an external force?
A force generated from outside the body.
What are the vertical forces?
Weight and reaction force
How does weight act as a force to the body? And give an example.
A gravitational force exerted on the body, pulling it towards the centre of the Earth. e.g an aquatic diver will experience the force of gravity pulling them done the pool.
What is a reaction force and give an example?
An equal and opposite reaction force that occurs when two bodies are in contact with each other. e.g when a footballer kicks a football there is an equal and opposite reaction force. Force is exerted against the ball and back on the foot by the ball.
What are the two horizontal forces?
Frictional force and air resistance force
What are the two types of frictional force?
Static and sliding
What is static friction? Give an example
The force exerted on one force by another when there is no motion between the two surfaces. The dry friction between the shoe and the tennis court but with no motion.
What is sliding friction? Give an example
The force exerted on one force by another when there is motion between the two surfaces. e.g when running 100 the push off from the feet is opposed by the friction in the opposite direction.
What factors can friction be affected by?
. The surface characteristics of the two bodies- e.g spikes have generate more friction
. The temperature of the two surfaces in contact. e.g the sweepers in curling increase the temp of the ice
. The mass of the objects that are sliding
What is air resistance?
A force that acts in the opposite direction to the motion of a body travelling through air.
What does amount air resistance depend on?
. The velocity of the moving body
. The cross-sectional area of the moving body
. The shape and the surface characteristics of the moving body
Where is weight drawn from on a free body diagram of forces?
From the centre of mass downwards
Where is reaction force drawn from on a free body diagram of forces?
Starts from where the two bodies are in contact with each other.
Where is friction drawn from on a free body diagram of forces?
Starts from where the two bodies are in contact and is opposite to the direction of any potential slipping.
Where is air resistance drawn from on a free body diagram of forces?
Drawn from the centre of mass opposing the direction of the motion of the body.
What is net force?
The resultant force acting on the body when all other forces have been considered.
What is a balanced net force?
When there are two or more forces acting on the body that are equal in size but opposite in direction.
What is an unbalanced net force?
When a force acting in one direction on a body is larger than a force acting in the opposite direction.
What diagram can show the effects of internal and external forces?
A vector diagram
What are the components of the vector diagram?
vertical force, horizontal force and vertical component.
What is the relationship between the components of the vector diagram?
The relation ship between the amount of vertical force and horizontal force provided by the muscles will lean the vertical component.
What is impulse?
The time it takes a force to be applied to an object or body.
How is impulse calculated?
Impulse (newton seconds) = Force X Time
In terms of Newton’s second law what does an increase of impulse mean?
An increase in the rate of change of momentum. causing a large change of velocity.