KIN 3514 Exam 2 - Part 2
What are the two real-life tests for power? What two derivatives of power are normally measured?
Margaria-kalamen test (stair climbing test) and Wingate test (cycling) Peak power and average power
Units: Momentum?
Momentum: kg *m/s
Positive work requires _________ caloric expenditure compared to negative work. Does a simple relationship between mechanical work and caloric expenditure exist?
More No
Impulse depends on both force and time, so if a different force is applied for the same time duration, the impulse is different, and a different ___________ occurs.
Movement
Which law is the principle of conservation of linear momentum: - Unless other external forces are applied, the total momentum of a system that comprises multiple bodies remains constant in time.
Newton's First Law
The maximum rate of motion achieved is called: What is the difference between speed and velocity? Which one is a scalar?
Peak rate of motion Speed (scalar) = distance (l)/ time Velocity = displacement/ time
What contraction does positive work? What contraction does negative work? What contraction does zero work?
Positive work = concentric Negative work = eccentric Zero work = isometric
Strain Energy is a special form of _________ energy. After being stretched (energy stored), when the object returns to the original shape, strain energy is converted into ____________ energy. What's the equation?
Potential energy Kinetic energy SE = 1/2kx^2
The capacity of an object to perform work because of its position, deformation, or configuration is: Energy of motion is:
Potential energy (PE = mgh) Kinetic energy (KE = 1/2mv^2)
Name cancellous bone, cortical bone, cartilage, tendon and ligament in order of toughness.
Toughest first: Cortical bone, ligament, tendon, cancellous bone, cartilage
The Margaria-Kalamen test is an assessment that monitors athlete's strength and power of lower extremities and helps coaches to see if the athlete's ____________ works. The test is conducted by having the athlete run up a flight of at least nine steps. The interval between the athlete placing a foot on the _______ and ________ step is timed.
Training program Third and ninth
A common application in sports is to calculate a coefficient of restitution (e) for a particular type of ball by dropping the ball from a known height and observing the rebound. What would the equation be in this case? Coefficient of restitution can also be calculated by looking at relative velocity before and after the collision. What would the equation be in this case?
e = √(height of rebound∕height of drop) e = (𝑉𝑎𝑓 − 𝑉𝑏𝑓)/(𝑉𝑎𝑖 − 𝑉𝑏𝑖 )
The degree to which the objects stick together during collision is influenced by: - The ____________ of the objects - __________ (ground contact) - Air ____________ - Gravity
- The elasticity of the objects - Friction (ground contact) - Air resistance - Gravity
The coefficient of restitution theoretically ranges in value from 0.00 to 1.00. 0.00 being perfectly ____________ 1.00 being perfectly ____________
0 - Inelastic 1 - Elastic
Name the two types of collisions?
1. Elastic: in which objects collide and bounce off of one another 2. Inelastic: in which objects collide and stick together
A viscoelastic material's deformation is affected by both the ___________ and the ___________ that it is subjected to a constant load. What gives most biological materials a degree of viscoelasticity?
A viscoelastic material's deformation is affected by both the rate of loading and the length of time that it is subjected to a constant load. Fluid components
Windgate test is an ___________ exercise test, most often performed on a stationary bicycle, that measures ________ anaerobic power and anaerobic capacity. The test consists of pedalling at maximum speed against a given resistance for 30 s.
Anaerobic; Peak
____________: occurs when two off-axis forces are applied such that tension stress is caused on one side of the system and compression stress occurs on the other side ____________: caused by two forces being applied in such a way that part of the system is rotated around its longitudinal axis in a direction opposite rotation of another part of the system
Bending: occurs when two off-axis forces are applied such that tension stress is caused on one side of the system and compression stress occurs on the other side Torsion: caused by two forces being applied in such a way that part of the system is rotated around its longitudinal axis in a direction opposite rotation of another part of the system
A parameter observed after reformation that indicates the ability of an object to return to its original shape after deformation
Coefficient of restitution (e)
The property of experiencing increasing strain (continued deformation) under a constant stress
Creep
The "sweet spot" of a bat is where the least amount of ball ______________ would occur on contact.
Deformation
Elastic region: the __________ portion of any given stress/strain curve Will the material to its original shape if the tensile stress is removed within this range? Yield point: point at which the applied stress can lead to permanent ________________ Plastic region: ___________ response of the material after the yield point Will the material to its original shape if the tensile stress is removed within this range?
Elastic - Linear; Yes Yield - permanent deformation Plastic - Non-linear; No
High strength, low ductility (brittle) = ___________ toughness Moderate strength, moderate ductility = ___________ toughness Low strength, high ductility = ___________ toughness
High strength, low ductility (brittle) = Low toughness Moderate strength, moderate ductility = High toughness Low strength, high ductility = Moderate toughness
What law says strain is proportional?
Hooke's Law
Area under a force-time graph
Impulse
In sports, reducing impulse by spreading force over more area or time reduces the risk of _________.
Injury
Newton's laws show how ___________ explain observed _____________.
Kinetics (forces) explain observed kinematics (like velocity, distance, etc.)
When catching something valuable we usually try to slow it down a bit. Hands give in a bit when catching to decelerate the object gradually. This is a concept of:
Linear impulse
What is linear impulse? What is the linear impulse-momentum equation?
The product of a force and the time interval over which the force acts (Force * change in time)
How is ductility represented graphically on a stress-strain curve?
Steepness of slope
Athletic prosthetics built for optimal energy return may be easier to design. There is minimal time between ___________ and ____________ energy.
Storing and releasing energy
On a stress-strain curve, which is the independent variable?
Strain
The magnitude of DEFORMATION as a result of the applied stress is ____________. What is the equation?
Strain; change in length/ original length ε =(𝑙𝑓−𝑙𝑖)/𝑙𝑖
____________ is the maximum stress or strain that a material can withstand without permanent deformation ____________ is the force per unit required to deform a material. ____________ is the total mechanical energy required to cause material failure.
Strength Ductility Toughness
The external force acting to deform the material is ___________. What is the equation?
Stress (σ) Force/Area
The ELASTIC modulus says _________ and _________ are proportional when system is elastic.
Stress and strain E = stress (σ) / strain (ε)
Young's modulus applies the elastic modulus when specifically referring to a condition of __________ stress. What is the equation?
Tension Y = (F/A) divided by (change in length/ initial length)
_______________: occurs when two forces are applied to a system in opposite directions away from each other The forces are colinear or have parallel lines of action but opposing directions such that the system is being "pulled apart." _______________: the result of two forces being applied to the system in opposite directions toward each other _______________: occurs due to application to two parallel forces that tend to simultaneously displace one part of a system in a direction opposite another part of the system
Tension stress: occurs when two forces are applied to a system in opposite directions away from each other The forces are colinear or have parallel lines of action but opposing directions such that the system is being "pulled apart." Compression stress: the result of two forces being applied to the system in opposite directions toward each other Shear stress: occurs due to application to two parallel forces that tend to simultaneously displace one part of a system in a direction opposite another part of the system
Mechanical work equation? Power equations (2)?
W = Force x distance Power = Work/ time Force x velocity
Explain the work-energy theorem.
W = ΔE = ΔKE + ΔPE + ΔTE
Whose law says disuse results in decreased muscle and bone mass vs. increased use results in greater muscle and bone mass?
Wolff's law
Energy is the capacity to do ____________.
Work
