Chapter 2 Flashcards
Define time.
A measure of temporal distance or succession between events.
Why does time exist?
Because of the second law of thermodynamics - the law of entropy. The fact that entropy is always increasing in a closed system (such as the universe) creates the arrow of time which moves in one direction: from order to disorder.
What must happen in order to reverse entropy (from disorder to order)?
Energy must be expended.
What is the definition of 1 day?
The amount of time for the earth to rotate around its axis.
How did the hours within a day become so?
The ancient Egyptians divided 1 day into 10 hours of daylight, 2 hours of twilight and 12 hours of night which divided a day into 24 hours.
Why is an hour divided into 60 minutes and a day into 60 seconds?
The ancient Babylonians measured astronomical events with a base-60 system.
What is the definition of 1 second?
The amount of time it takes for a cesium-133 atom to transition from 1 state to another.
When did the Babylonians develop trigonometry?
1000 years before Pythagoras
How did the Babylonians accomplish complex trigonometry calculations?
They used a base-60 system with more prime number divisors.
Define a time series analysis
An analysis of what changed in space at two or more different points in time.
Define rhythm
1 - the temporal sequence of events within a task
2 - relative timing between events within a task
How we do something
Define tempo
The total time required to perform a task, or the frequency of performing a task
(How quickly we do something)
Apply the concepts of tempo and rhythm to a squat - what are each describing?
Rhythm refers to the relative timing between events within a movement. In a squat, rhythm would describe the relative timing to perform the concentric and eccentric phases.
Tempo refers to the absolute time to perform a task. For a squat the tempo would describe the amount of time it takes to perform the squat.
When trying to perform a squat faster, the rhythm will increase while the tempo will stay the same - true or false.
False - the tempo (total time) will decrease because you will be performing the squat faster. The rhythm (relative timing between eccentric and concentric phases) will stay the same.
When training athletes who perform cyclic activities, is rhythm or tempo more important to focus on?
Rhythm - as it gives a good indication of training age, expertise and even abnormalities.
For example, a novice swimmer will use a variety of rhythms as they have not mastered the swimming stroke and do not have the coordination of an experienced swimmer. Rhythm can also be assessed in well-trained individuals to give objective indications of fatigue or injury.
remember even though tempo increases for cyclic activities, rhythm will stay the same
Define frequency
The rate at which an event occurs or is repeated over a particular time period. F=events/time
What physiological measurement is an example of frequency?
Heart rate, breathing rate ect.
What is the SI unit for frequency?
Hertz (Hz) = events/second
Describe a gait cycle
One gait cycle involves two phases - stance and swing - describing the motion of a single lower limb.
In a normal gait, about 60% of the time is spent in stance phase while 40% is spent in swing phase.
Abnormalities in this rhythm can indicate injuries or ailments.
The stride frequency of the fastest sprinter in the world is greater than that of their competitors - true or false.
False - their stride frequency is lower, giving them more time to generate power with each stance phase.
When learning a new activity should tempo or rhythm be developed first?
When learning a new activity, rhythm is most important to develop first and then you can increase the tempo.
What are 3 ways we could manipulate an individuals rhythm or tempo?
Metronome, music or verbal cues
