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Question Bank for Written Student Assessment and
Evaluation
Quiz: How Much Do You Know About the Science of Biomechanics?
1. A qualitative analysis requires:
A) a framework within which skilled performances can be observed
B) a set of principles within which movement can be analyzed
C) a checklist to use when identifying errors
D) techniques to use to correct errors in performance
E) all of the above
Answer: E
2. The study of _________ describes spatial and timing characteristics of motion. Answer:
kinematics
3. For athletes who are in contact with the ground or other earth-bound objects (e.g., diving
board) a particle model is used to represent their bodies. Answer: false (Correct: stick figure)
4. Which of the following statements about weight versus mass is false:
A) Mass is a measure of inertia.
B) Weight is a measure of the force of gravity.
C) Weight is measured in Newtons (N).
D) Weight varies directly with the magnitude of the acceleration due to gravity.
E) None of the above
Answer: E
5. The line about which bodies rotate is called the _________ of rotation. Answer: axis
6. Forces that act through a body’s centre of mass will cause linear motion. Answer: true
7. Which of the following is an example of a first class lever:
A) a pair of scissors
B) a nutcracker
C) a pair of tweezers
D) a wheelbarrow
E) a snow shovel
Answer: A
8. A _________ class lever exists when the applied force and the resistance are on the same side
of the axis, but the applied force is closer to the axis. Answer: third
9. According to Newton’s first law of motion, objects continue to move in a state of constant
velocity unless acted upon by an external force. Answer: true
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10. Which of the following statements regarding the relationship between force, mass, and
acceleration is false:
A) The greater the force applied to an object that has the same mass, the greater the acceleration
of the object.
B) As the mass of the object decreases, it experiences less acceleration when a constant force is
applied.
C) For angular movements, the angular acceleration of a body is directly proportional to the
moment of force causing it and takes place in the same direction as the moment of force.
D) As the mass of the object decreases, less force needs to be generated in order to assume the
same acceleration.
E) None of the above.
Answer: B
11. The region of relative motion between fluid molecules around an object is called the
_________. Answer: boundary layer
12. Profile drag is the main form of drag in fast-moving athletic events, such as skiing, cycling,
running, and all projectile events. Answer: true
13. Which of the following statements about the Magnus effect is false:
A) A ball with topspin produces a Magnus force downward.
B) For sidespins, a ball will curve towards the spinning side.
C) A backspin creates high pressure on the top of the ball and low pressure on the bottom of the
ball.
D) If the flow within the boundary layer is in the opposite direction to the relative air flow, the
air is slowed by friction forces.
E) None of the above.
Answer: C
14. The process whereby the body’s state of equilibrium is controlled for a given purpose is
called _________. Answer: balance
15. Determining the skill objective and the correct execution of a skill is part of the evaluation
phase of quality instruction. Answer: false (Correct: preparation)
16. Explain how an athlete can increase his stability while in static equilibrium and while in
dynamic equilibrium. Answer: To increase stability while in static equilibrium, an athlete can
do the following: (1) Increase the size of his base of support. (2) Increase his body mass. (3)
Lower his centre of gravity. (4) Increase the horizontal distance between the point where a
vertical line from his centre of mass intersects his base of support and the outside edge of his
base of support. To increase stability while in dynamic equilibrium, an athlete can do the
following: (1) Extend the body’s base of support in the direction of external horizontal forces,
which may be given or received. (2) Adopt a starting position in which the centre of gravity is
close to the edge of the base of support whenever quick acceleration is important. (3) Shift the
line of gravity towards an oncoming force. (4) Use reflex movements to help regain loss of
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balance when tripping or falling (e.g., windmill action of the arms made by a gymnast falling off
a beam) or to create a new base of support.
Multiple Choice Questions
1. Which of the following is not a high-tech method of assessment used by biomechanists to
collect numeric measurements of performance:
A) computerized force-measuring platforms
B) high-speed video recording
C) electromyography
D) computerized motion analysis
E) none of the above
Answer: E
2. Internal forces refer to:
A) forces generated by muscles pulling on bones
B) forces acting from without, such as gravity
C) forces from any body contact with the environment
D) forces exerted across joint surfaces
E) both A and D
Answer: E
3. To represent the total body configuration for gross motor skills that occur in two dimensions, a
_________ is used.
A) stick figure model
B) particle model
C) rigid body segment model
D) composite diagram
E) none of the above
Answer: A
4. For sophisticated three-dimensional (3D) analyses, biomechanists employ a:
A) stick figure model
B) particle model
C) rigid body segment model
D) composite diagram
E) none of the above
Answer: C
5. In general, the centre of mass is located about _________ above the groin area.
A) 5 cm
B) 10 cm
C) 15 cm
D) 20 cm
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E) none of the above
Answer: C
6. Which of the following objects has the most inertia:
A) a tennis ball
B) a 1-kg medicine ball
C) a ping-pong ball
D) a basketball
E) a beach ball
Answer: B
7. When a body moves on a circular path and in the same direction – but not at the same time –
then the body is experiencing _________ motion.
A) curvilinear
B) angular
C) general
D) both A and B
E) none of the above
Answer: B
8. A combination of linear and angular motion is referred to as:
A) translation
B) rotation
C) general motion
D) curvilinear motion
E) rectilinear motion
Answer: C
9. When a force causes angular motion, the effect is known as:
A) a torque
B) a pivot
C) a moment of force
D) curvilinear motion
E) both A and C
Answer: E
10. The resistance arm (RA) is:
A) the distance from the axis to where the force is applied
B) the distance from the axis to where the resistance is applied
C) the distance from the fulcrum to where the force is applied
D) the distance from the fulcrum to where the weight is applied
E) both B and D
Answer: E
11. The amount of torque that can be generated is influenced by:
A) the length of the force arm
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B) the length of the resistance arm
C) the magnitude of force
D) both A and C
E) both B and C
Answer: D
12. Which of the following statements regarding lever systems are true:
i. Angular motion will occur if the applied force is greater than the resistance to rotation
at the fulcrum.
ii. In some levers, the application of a relatively small amount of force can overcome a relatively
large resistive force.
iii. The fundamental components for any angular motion are a fulcrum and a pivot point.
iv. The amount of torque produced depends on the force generated multiplied by the length of
the force arm.
v. The shorter the force arm, the greater a lever’s mechanical advantage.
A) i, iii
B) i, iii, v
C) i, ii, iv
D) i, ii, v
E) i, v
Answer: C
13. Which of the following is an example of a second class lever:
A) a pair of scissors
B) a nutcracker
C) a pair of tweezers
D) a teeter-totter
E) a snow shovel
Answer: B
14. Newton’s second law of motion states that:
A) the acceleration a body experiences is directly proportional to the force causing it and takes
place in the same direction as the force
B) an object at rest will tend to stay at rest
C) every action has an equal and opposite reaction
D) an object in motion will tend to stay in motion
E) both B and D
Answer: A
15. Which of the following equations is correct:
A) force = mass / acceleration
B) acceleration = force / mass
C) acceleration = mass / force
D) acceleration = force x mass
E) both A and D
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Answer: B
16. What is another name for surface drag?
A) shape drag
B) pressure drag
C) skin friction
D) form drag
E) none of the above
Answer: C
17. Both surface drag and profile drag are proportional to:
A) the velocity of air flow
B) the size of the object
C) the smoothness of the surface
D) all of the above
E) B and C only
Answer: D
18. Which of the following is not a technique for reducing drag.
A) assuming a tuck position while skiing
B) sledding while supine
C) drafting
D) wearing a streamlined body suit
E) none of the above
Answer: E
19. Which of the following statements regarding equilibrium is true:
A) Equilibrium describes the state of a system that is not experiencing any change in its direction
or speed.
B) Dynamic equilibrium describes the state of a system that is at rest.
C) Balance is a measure of the ease or difficulty with which equilibrium can be disturbed.
D) Stability is the process whereby the body’s state of equilibrium is controlled for a given
purpose.
E) None of the above.
Answer: A
20. To control the state of equilibrium, we constantly manipulate which two factors?
A) balance and stability
B) stability and base of support
C) base of support and line of gravity
D) line of gravity and balance
E) balance and base of support
Answer: C
21. To increase the stability in a static equilibrium, an athlete must:
A) increase body mass
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B) increase the vertical distance between where a vertical line from the centre of mass intersects
the base of support and the outside edge of the base of support
C) increase the horizontal distance between where the line of gravity intersects the base of
support and the outside edge of the base of support
D) all of the above
E) A and C only
Answer: E
22. Which of the following statements regarding qualitative analysis is false:
A) Qualitative analysis is a subjective and systematic evaluation of a movement or skill.
B) Video recording is a tool used for qualitative analysis.
C) The qualitative approach to movement analysis is based on the instructor’s thorough
understanding of the movement being evaluated.
D) An integrated model of qualitative analysis includes preparation and error correction.
E) None of the above.
Answer: E
23. The four major aspects of quality instruction are:
A) research, preparation, observation, and error correction
B) preparation, observation, evaluation, and error correction
C) preparation, error detection, feedback, and evaluation
D) experience, observation, assessment, and error correction
E) preparation, communication, evaluation, and error correction
Answer: B
24. When observing an athlete’s performance, the coach should begin by:
A) determining the skill objective
B) identifying the key body movements involved in each phase of the skill
C) determining the correct execution of the skill
D) analyzing the whole skill
E) breaking the skill into phases
Answer: D
25. The most common technique for error detection is:
A) using a chart or checklist
B) asking the athlete for feedback
C) observing the skill being performed
D) comparing performance against a model
E) performing a biomechanical analysis
Answer: C
Fill in the Blank Questions
1. Electromyography (EMG) measures and records the electrical activity generated by the
_________ as they are stimulated by the athlete’s nervous system. Answer: muscles
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2. Biomechanics is a science that examines the _________ and _________ forces acting on the
human body. Answer: internal; external
3. The _________ model is a simple dot representing the centre of mass of the body or object.
Answer: particle
4. For most sophisticated three-dimensional (3-D) analyses, biomechanists employ a _________
model. Answer: rigid body segment
5. The point around which the body’s mass is equally distributed in all directions is known as the
_________. Answer: centre of mass or centre of gravity
6. The measure of how much matter an object has is its _________. Answer: mass
7. The force of attraction between two bodies is _________. Answer: gravity
8. The inertia of rotating objects is measured by their _________ of inertia. Answer: moment
9. When all parts of the body move the same distance, in the same direction, and at the same time
it is known as _________ motion. Answer: linear
10. A _________ is any action, a push or pull, that tends to cause an object to change its state of
motion by experiencing acceleration. Answer: force
11. The fundamental components for any angular motion are a fulcrum and a _________.
Answer: lever
12. Complete the following equation: _________ = force arm x _________. Answer: torque;
force
13. A wheelbarrow is an example of a _________ class lever. Answer: second
14. Newton’s first law of motion describes the relationship between _________ and _________.
Answer: inertia; force
15. Newton’s third law is the law of _________. Answer: action–reaction
16. _________ drag is caused by the size and shape of the object and the air turbulence produced
by its shape as it moves through the air. Answer: Profile
17. A smooth, layered flow pattern of a fluid around an object is called _________ flow.
Answer: laminar
18. The technique of taking advantage of the region of air shielded by another athlete’s body is
known as _________. Answer: drafting
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19. The uneven surface of a spinning tennis ball creates a _________ force that is directed from
high to low pressure. Answer: Magnus
20. A system that is not experiencing any change in its direction or speed is said to be in a state
of _________. Answer: equilibrium
21. An imaginary vertical line that passes through the body’s centre of mass is the _________.
Answer: line of gravity
22. Whenever quick acceleration is important, an athlete should adopt a starting position in
which the centre of gravity is close to the edge of the _________. Answer: base of support
23. The study of human motion in the absence of measuring is known as _________. Answer:
qualitative analysis
24. Scoring a goal in hockey is an example of a skill _________. Answer: objective
25. When analyzing a skill, identify the key body movements involved in each _________ of the
skill. Answer: phase
True or False Questions
1. A quantitative analysis is intended for use by researchers. Answer: true
2. Kinematics focuses on the various forces that are associated with a movement. Answer: false
(Correct: Kinetics)
3. A bone-on-bone force exerted across a joint surface is an example of an internal force.
Answer: true
4. Since particle models involve only the centre of mass of an object, they are limited to bodies
in flight. Answer: true
5. Your centre of mass is always found inside the body. Answer: false (Correct: not always)
6. Females generally have a lower centre of gravity than males. Answer: true
7. Objects are reluctant to change their state of motion from moving faster or slower, a property
known as equilibrium. Answer: false (Correct: inertia)
8. Layout dives are harder to perform than the same dive in the tuck position because the
athlete’s body parts are farther away from the moment of inertia. Answer: false (Correct:
rotating axis or centre of mass)
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9. Another term often used for angular motion is translation. Answer: false (Correct: linear)
10. Most athletic activities involve general motion. Answer: true
11. The force arm (FA) is the distance from the lever to where the force is applied. Answer:
false (Correct: axis or fulcrum)
12. In a second class lever, the applied force and the resistance are located on opposite sides of
the axis. Answer: false (Correct: first class)
13. Knee flexion is an example of a third class lever. Answer: true
14. Sprinters must experience a large, balanced external force acting on their body mass at the
start of a race in order to accelerate down the track. Answer: false (Correct: unbalanced)
15. Drag is a fluid force. Answer: true
16. Laminant flow within the boundary layer will change the flow conditions. Answer: false
(Correct: Turbulent)
17. A slightly rough surface has lower friction drag than a perfectly smooth surface. Answer:
true
18. A backspin creates high pressure on the top of the ball and low pressure on the bottom of the
ball. Answer: false (Correct: topspin)
19. Fluid molecules rubbing against fluid molecules results in much lower friction. Answer: true
20. Static equilibrium describes the state of a system that is moving with constant velocity.
Answer: false (Correct: Dynamic)
21. Balance is a measure of the ease or difficulty with which equilibrium can be disturbed.
Answer: false (Correct: Stability)
22. If the line of gravity passes through some part of the body’s base of support, then the body
will be balanced. Answer: true
23. To increase stability in dynamic equilibrium, an athlete must extend the body’s base of
support in the direction of external horizontal forces. Answer: true
24. Most skills, whether discrete or continuous, can be divided into phases. Answer: false
(Correct: All)
25. If several errors occur in a performance, the coach should begin with the final error. Answer:
false (Correct: earliest or first)
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Other Types of Questions
1. Explain the importance of biomechanics for human movement, sport, and performance.
Answer: Biomechanics describes the causes and effects of how the body moves; it examines the
internal and external forces acting on the human body and the effects produced by these forces;
and it allows us to understand why humans walk the way we do and what effect gravity has on
the human musculoskeletal system. Sport biomechanists have also contributed invaluably to
improving performances in selected sports, such as wheel and helmet designs for cycling,
optimal body positioning for ski jumping during the flight phase, and the most effective technique
for throwing a discus or baseball. Biomechanics has significantly added to our knowledge of
human movement, from analyzing technique to developing innovative equipment designs.
Understanding the mechanical principles that underlie human movement can help answer
questions related to human health and performance.
2. What do force platforms measure? Why do biomechanists generate force–time graphs? What
does electromyography measure? What is the importance of computerized motion analysis
systems?
Answer: Force platforms measure the forces generated on the ground by athletes performing
athletic skills. Force–time graphs enable the biomechanist to analyze force patterns generated
by the athlete and reveal performance faults. Electromyography (EMG) measures and records
the electrical activity generated by the muscles as they are stimulated by the athlete’s nervous
system. Computerized motion analysis systems allow multiple forms of biomechanical
instrumentation to be synchronized for more sophisticated collection of data from athletic
performance. The system generates synchronized data related to the athlete’s body positions,
joint angles, movement speeds, accelerations, forces, torques, and so on.
3. What is the centre of mass, and why is its location important?
Answer: The point around which the body’s mass is equally distributed in all directions is
known as the centre of mass, or centre of gravity (CG). The location of the CG in the human
body is of interest because a body behaves as though all of its mass were concentrated at the
CG. Therefore, the force of gravity acting on this point of mass would be the same as the force of
gravity acting on the total body.
4. Explain the difference between mass and weight.
Answer: Mass is a measure of inertia, while weight is a measure of the force of gravity (g)
acting on the body. Mass is measured in kilograms (kg), while weight is measured in Newtons
(N). A person’s weight varies directly with the magnitude of the acceleration due to gravity (9.8
m/s2). Thus in space where there is no acceleration experienced due to gravity we weigh 0 N but
have the same mass as we do on earth.
5. Using a soccer ball/tennis ball comparison and a diver as examples, discuss the factors that
affect the inertia of rotating objects.
Answer: The inertia of rotating objects depends on their mass and how their mass is distributed
about their axis of rotation. It is more difficult to change the state of rotation of a soccer ball,
compared to a tennis ball, because it is more massive and its mass is found farther away from
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any axis of rotation (i.e., the diameter of the soccer ball is larger). Similarly, a layout dive is
harder to perform than the same dive in the tuck position because the athlete’s body parts are
farther away from the rotating axis (which passes through the athlete’s centre of mass), giving
the layout diver a greater moment of inertia.
6. What causes linear and angular motion in the human body?
Answer: The cause of motion of the human body is the application of forces, which can be
internal or external. A force is any action, a push or pull, that tends to cause an object to change
its state of motion by experiencing acceleration. Forces that act through a body’s centre of mass
will cause linear motion, such as throwing a ball or pushing a cart. Forces that do not go
through the centre of mass, or pivot point, of an object cause motion about an axis of rotation
(angular motion).
7. Define force arm, resistance arm, and torque. Label the force, resistance, axis, force arm, and
resistance arm on the following diagram.
Answer: The force arm (FA) is the distance from the axis to where the force is applied. The
resistance arm (RA) is the distance from the axis to where the resistance (R) or weight is applied.
Torque is a rotary force produced when a lever rotates around an axis. It is the product of force
arm and force.
8. Define the boundary layer, and describe the flow that occurs within it.
Answer: The boundary layer is the region of relative motion between adjacent layers of fluid.
Two types of flow can occur within the boundary layer: laminar flow and turbulent flow. If an
object is small, streamlined, smooth, and relatively slow, then laminar flow will occur. Laminar
flow is a smooth, layered flow pattern of a fluid around a person or an object with no wake or
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other disturbance. Most human activities, however, move too fast to allow laminar flow to occur.
They generate turbulent flow within the boundary layer that changes the flow conditions.
9. What is drafting? Why do athletes such as runners and cyclists use this technique?
Answer: Many sports involve drafting, the technique of taking advantage of the region of air
shielded by another athlete’s body. Research conducted in wind tunnels has shown that running
within 1 metre of the runner ahead can save an athlete almost 6 percent of energy costs.
Likewise, a cyclist riding close behind another will encounter a greatly reduced profile drag. The
drafting athletes do not need to work as hard against air resistance as the person in front of
them.
10. What techniques do coaches use for error detection? What are good practices when
correcting an athlete?
Answer: The most common technique for error detection is visual, by using direct observation,
analyzing videos, or observing traces or marks left by the athlete. Other error detection
techniques include observing the outcome or follow-through, using a chart or checklist, or
asking the athletes what they felt about their performance. When correcting, coaches should use
positive and specific language appropriate to the age, developmental level, and competitive level
of their athletes. Conscientious coaches ask for feedback to check if the correction instructions
were received as intended. They also try to minimize any distractions in the environment before
correcting any errors. Good coaches are also familiar with the latest technology and use it in
their coaching.
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