Biomechanics Quiz Questions

A 100 kg shot-putter pushes on a 4 kg shot with a force of 500 N forward and a force of 866 N upward. How large is the resultant force acting on the shot?

1,000 N

A softball is fouled off a bat with a horizontal velocity of 15 m/s and a vertical velocity of 20 m/s. What is the resultant velocity of the ball?

25 m/s

When knee flexion is increased during sprinting, what happens to the moment of inertia of the leg about the hip?

The moment of inertia decreases

During a 400-m track race, the sprinters in lane 1 (the inside lane) and lane 8 (the outside lane) have the same linear velocity of 9.5 m/s at the apex of the curve. Which sprinter will experience the greatest radial acceleration towards the inside of the track? A. The sprinter in lane 1. B. The sprinter in lane 8. C. Both sprinters will experience the same radial acceleration.

The sprinter in lane 1

T/F: The human body cannot move unless a force is applied to it.

True

The vertical force that, when present, always acts upward on the human body is:

buoyant force

which of the following motions occurs primarily in the frontal plane? A. cartwheel B. running C. pirouette D. all of the above

cartwheel

A force can be:

either a push or a pull

Torque is the angular equivalent of what?

force

Most human movement falls into which category?

general movement

The study of the force and energy factors associated with systems in motion is called

kinetics

A cyclist in the Tour de France riding a bicycle forward in a straight line would be moving in the...sagittal

sagittal plane

Where is the series elastic component of a muscle found?

tendon

A 60 kg dancer applies a horizontal force of -800 N on the dance floor. The dancer's acceleration will be:

+13.33 m/s2

At 3 s into a run, a football player is traveling at +3 m/s. Four seconds later, the player is traveling at -5 m/s. What is the acceleration of the football player?

-2.0 m/s^2

If a scale shows that an individual has a mass of 68 kg, what is that individual's weight?

-667 N

When a runner has completed two full laps around a 400 m track, what is his/her displacement with respect to the starting position? A. 800 m B. 400 m multiplied by 2π C. 0 m D. Need more information to calculate.

0 m

How long would a 100 N·m muscle torque need to be applied to change the angular momentum of the leg from 10 kg·m2/s to 35 kg·m2/s?

0.25 s Based on the angular impulse-momentum relationship, ∑T Δt = ΔH. ∑T Δt = Hf - Hi (100 N·m)Δt = 35 kg·m2/s - 10 kg·m2/s (100 N·m)Δt = 25 kg·m2/s Δt = (25 kg·m2/s)/(100 N·m) = 0.25 s

A 115-kg football player is running towards you at 12 m/s. What impulse will you have to generate to stop him?

1,380 N·s

A high jumper with a body weight of 820 N exerts an average vertical force of 1,640 N down on the ground for 0.75 s. The average vertical force exerted on the high jumper by the ground is:

1,640 N

An individual is running around a turn with an 11-m radius at 3.75 m/s. What is the runner's centripetal (radial) acceleration?

1.28 m/s2

During a drive by golfer Justin Spieth, the angular velocity of his club is zero at the top of the backswing and 30 rad/s at the bottom of the downswing just before impact with the ball. If the downswing lasts 0.30 s, what is the average angular acceleration of the club during the downswing?

100 rad/s^2

A weightlifter is attempting a biceps curl with a 200 N barbell. The moment arm of the barbell about the elbow joint is 40 cm. The moment arm of the elbow flexor muscles is 4 cm. How much force must be produced by these muscles to hold the barbell in static equilibrium?

2,000 N

A discus thrower exerts a torque of 5 N·m on a 2 kg discus. The discus has a radius of gyration of 0.1 m. If this is the only torque exerted on the discus, what is its angular acceleration?

250 rad/s2

A pole-vaulter clears a crossbar and takes 1.0 s to fall from the apex of his flight to the landing pit. How far did he fall during this second?

4.905 m

A basketball player shoots from beyond the 3-point arc. The ball leaves the hand with an initial velocity of 8 m/s angled from 52° from the horizontal. What is the horizontal velocity of the basketball?

4.93 m/s

Kim (mass = 55 kg) is spinning on the ice with an angular velocity of 20 rad/s about her longitudinal axis when she abducts her arms and doubles her radius of gyration about her longitudinal axis from 30 cm to 60 cm. If her angular momentum is conserved, what is her angular velocity about her longitudinal axis after she abducts her arms?

5 rad/s

A swimmer is traveling with an average velocity of 3.2 m/s. How far does the swimmer travel in 3 s?

9.6 m

Which of the following is true regarding the human body's anatomical reference position? A. the palms face forward B. erect standing posture C. the starting position for describing joint motion D. all of these are true

All are true

Which of the following is true regarding the stretch-shortening cycle (SSC)? A. When a muscle is stretched just prior to contraction, the resulting contraction is more forceful. B. An eccentric contraction is followed by a concentric contraction. C. The SSC promotes storage of elastic energy. D. All of the above answers are correct.

All of the above are correct

During a discus throw, Anthony's arm rotates 30 rad/s, and the discus is 1.1 m from the axis of rotation when he releases it. John's arm rotates 20 rad/s, and the discus is 1.5 m from the axis of rotation when he releases it. Whose discus throw is most likely to be farther? A. Anthony's throw B. John's throw C. Both throws will travel the same distance

Anthony's throw Anthony: vT = rω = (1.1 m)(30 rad/s) = 33 m/s John: vT = rω = (1.5 m)(20 rad/s) = 30 m/s

which of the following is not an example of qualitative analysis? A. a coach correcting a basketball free throw B. A sport scientist measuring the force-time profile of a weight lifter performing a snatch C. a PT observing a patient perform a rehabilitation exercise D. All of the above

B.

On a rigid body segment that is undergoing angular motion (such as the forearm during a biceps curl exercise), which of the following statements is true? A. The linear displacement of any two points on the body segment would be equal. B. The angular displacement of any two points on the body segment would be equal. C. The linear velocity of any two points on the body segment would be equal. D. The angular velocity of any two points on the body segment would be different. E. None of the above

B. The angular displacement of any two points on the body segment would be equal.

which of the following are examples of a static analysis of human movement? A. a weight lifter lifting a barbell over his/her head during a clean and jerk B. a downhill ski racer performing a "wall sit" isometric exercise C. An older individual losing his/her balance while walking down D. none of the above

B. a downhill ski racer

Space travel is associated with a reduction in bone mineral content because: A. space diets are low in calcium. B. microgravity reduces loading on bones. C. electrical activity in space affects estrogen and testosterone levels. D. all of the above interact to reduce bone mineral content. E. None of the above affect bone mineral content

B. microgravity reduces loading on bones.

when stress is maintained in the .... muscle maintains the same force-generating capability, bone mineral content stays the same, and tendons and ligaments maintain their ability to withstand tensile stress A. pathologic underload zone B. physiologic loading zone C. physiologic training zone D. pathologic overload zone

B. physiological loading zone

Bill lifts a 1000 N barbell 1.5 m in 1.0 s, while Bob lifts a 1400 N barbell 2.0 m in 2.0 s. Whose lift was more powerful?

Bill's lift was more powerful

Which of the following is a projectile motion? A. a badminton shuttlecock during flight B. A long jumper while in the air. C. A drone. D. Both a badminton shuttlecock ("birdie") during flight and a long jumper while in the air. E. All of the above.

Both a badminton shuttlecock ("birdie") during flight and a long jumper while in the air.

Third class lever systems in the human body favor which of the following? A. Speed B. Range of motion C. Strength D. Both speed and range of motion E. All of the above

Both speed and range of motion

Which of the following could be considered in a kinematic study of a sprinter? A. the power of a sprinter during each segment of a race B. the force exerted against the starting blocks by the sprinter at the beginning of a race C. the angular motion of the sprinter's leg during a race D. all of the above

C.

Which statement is true? A. Increasing the surface area over which a force is distributed increases the amount of stress acting on the surface. B. Decreasing the surface area over which a force is distributed decreases the amount of stress acting on the surface. C. Increasing the surface area over which a force is distributed decreases the amount of stress acting on the surface. D. All of the above are true. E. None of the above is true.

C. Increasing the surface area over which a force is distributed decreases the amount of stress acting on the surface.

During foot support in running, the momentum of the body mass above the knee joint tends to cause the femur to slide forward over the tibial plateau. As a result, the hyaline cartilage of the knee joint and the menisci are subjected to __________________ stress. A. compressive B. tensile C. shear D. the hyaline cartilage of the knee joint and menisci are not subjected to any stress

C. shear

Which of the following topics might be studied by biomechanists? A. optimal form during the pole vault B. forces on the spine during lifting C. the mechanics of the jump shot in basketball D. all of the above

D.

which of the following is the most appropriate definite of biomechanics? A. the study of human movement B. the study of biological organisms C. the study of movement mechanics D. the study of the mechanical aspects of biological organisms

D.

The force applied to a biological material such as bone, cartilage, tendon, or ligament will cause a. stress b. strain C. neither stress nor strain D. both stress and strain

D. both stress and strain

which of the following is an extrinsic factor related to injury development? A. a person's previous history of injury B. an individual's current fitness level C. an individual's joint flexibility D. the footwear that a person wears during training

D. the footwear that a person wears during training

If the angular velocity is the same for both golf swings, will a 9-iron (36 inches long) or a driver (43.5 inches long) have a greater linear club head velocity resulting in a longer shot? A. 9-iron B. Driver C. Both clubs will have an equal linear club head velocity D. Need more information

Driver

What type of muscle action is employed by the elbow flexors when slowly lowering your backpack to your desk? A. Concentric B. Eccentric C. Isometric D. Isokinetic

Eccentric

T/F: A skater who is spinning in the air during a jump can increase her angular momentum by extending her arms and legs.

False

T/F: All biomechanical analyses must be quantitative in nature

False

T/F: It is not possible to shift an athlete's center of gravity into a position where it is temporarily outside the body.

False

T/F: Running speed is increased by first increasing stride rate (or step rate) and then stride length (or step length).

False

T/F: The fluid force that resists the forward motion of a swimmer is lift.

False

T/F: The rate at which work is performed is termed potential energy.

False

T/F: axial skeleton includes the head, trunk and upper extremities

False

T/F: fast twitch muscle fibers are always recruited first for fast movements

False

T/F: immobilization has little effect on tendons and ligaments

False

T/F: the epimysium is the connective tissue sheath surrounding a single muscle fiber

False

T/F: At the apex of the trajectory of a punted football, the vertical velocity of the football is at its maximum.

False vertical velocity is 0

T/F: angular motion only occurs about a joint center (axis of rotation)

False; angular motion of the body/ limb segment/ object can take place around an axis running through a joint, through the center of gravity or about an external axis rotation

T/F: The angular displacement would be 900 degrees for a diver completing 2 ½ somersaults.

False; the angular distance = 900 degrees and the angular displacement = 180 degrees for a diver competing 2 ½ somersaults.

A gymnast dismounts the uneven parallel bars with some angular momentum about her transverse axis. Just after release, she is in a piked position (where a gymnast is essentially folded in half at her hips). She then extends into a layout position before she lands. What happens as a result of this action?

Her moment of inertia increases and she rotates slower

How does wearing batting gloves increase the friction between the hands and a bat?

It increases the coefficient of static friction (μs)

How does adding weight to the back of a pickup truck increase the friction between the tires and an icy road?

It increases the normal reaction force (N)

Description of a patient's ankle range of motion is an example of: A. dynamics B. Kinematics C. Kinetics D. Mechanics

Kinematics

Which is not a valid unit of angular velocity? A. Meters per second B. Degrees per second C. Radians per second D. Revolutions per minute

Meters per second

Which of the following, when present, is NOT an external force applied to a runner? A. Ground reaction force B. Weight C. Friction D. Muscle force E. All of the above are external forces

Muscle force

If the static coefficient of friction of a basketball shoe on a particular playing surface is 0.51 and the normal force is 820 N, what is the minimum horizontal force is necessary to cause the shoe to slide?

418.2 N

A 75-kg high jumper with a vertical takeoff velocity of 7.0 m/s raises his center of mass 2.5 m to clear the bar. What are his potential energy and kinetic energy at the moment he clears the bar?

PE = 1,839.4 J; KE = 0 J

When the final velocity of a swimmer is larger than his/her initial velocity, the acceleration is what? (assume swimmer is moving in a positive direction) A. zero B. negative C. Positive D. average

Positive

The research on the length-tension relationship of the muscle-tendon unit indicates that the muscle-tendon unit is capable of generating maximal force when the muscle is: A. fully shortened. B. slightly shorter than resting length. C. at resting length. D. slightly longer than resting length. E. fully lengthened.

Slightly longer than resting length Max tension can be developed in a whole muscle when it is just a little longer than (about 120% of) its resting length

A biomechanist must have a sound knowledge of anatomy, physics, and mathematics.

TRUE

Which of the following is a unique behavioral property of skeletal muscle tissue? A. Extensibility B. Elasticity C. Irritability D. The ability to develop tension E. All of the above answers are correct.

The ability to develop tension

When two lacrosse players collide head-on and then continue to travel collectively in the original direction of motion of one of the players, what factor determines the direction of collective motion of the players after the collision?

The relative momentums of the two players

When drawing a free body diagram of a dancer pushing off the floor in a jump, which of the following is NOT a force to be considered? A. The dancer's weight B. The push of the floor on the dancer's foot. C. The speed of the dancer across the floor D. The friction of the floor on the dancer's shoe

The speed of the dancer across the floor

T/F: A barbell with a mass of 100 kg cannot be lifted unless the force applied is greater than 981 N.

True

T/F: As the velocity of a concentric muscle action increases, the maximum force a muscle can produce decreases

True

T/F: The peak vertical ground reaction force in running is much greater than in walking.

True

T/F: The principle moment of inertia of the human body is smallest around the longitudinal axis.

True

T/F: When solving kinematics problems related to the relationship between linear and angular motion, the units for angular motion must be in revolutions.

True

T/F: stiffness of a biological material can be determined by calculating the slope of the linear portion of the stress-strain curve

True

T/F: the gradual development of carpal tunnel syndrome from repeated data processing with a keyboard is an example of overuse injury

True

which of the following limb movements are predominant during "jumping jacks"? A. abduction and adduction B. flexion and abduction C. extension and adduction D. flexion and extension

abduction and adduction

biomechanical research has contributed to which of the following? injury prevention enhanced sport performance equipment design all of the above

all of the above

which of the following could be define by a movement analyst as a mechanical system? A. the entire human body B. the right arm of a javelin thrower C. a projected ball D. all of the above

all of the above

A change in angle in a particular direction is __________________, while the rate of change in angle in that direction is __________________. A. position, velocity B. displacement, angle C. angular displacement, angular velocity D. angular velocity, angular displacement

angular displacement, angular velocity

bone is strongest in resisting ... stress

compressive

What term best describes linear motion along a curved line such as a sprinter running the curve on a track?

curvilinear

the order of max potential force output (from largest to smallest) by muscle action type is

eccentric > isometric > concentric

As a joint is moved through its range of motion when strength training with free weights, such as doing an arm curl exercise, the moment arm for the muscle crossing the joint will get:

either longer or shorter

Which type of muscle could serve as an antagonist of a flexor?

extensor

Which of the following is not a kinematic quantity? A. force B. Displacement C. Velocity D. acceleration

force

When applying rigid-body mechanics to the study of human beings, which assumption is made? A. The body does not deform by bending, stretching, or compressing. B. The body segments are flexible links. C. The joints provide friction during movement. D. The body deforms by bending, stretching, or compressing. E. All of the above are assumed.

A. The body does not deform by bending, stretching, or compressing.

A standing person has __________________ forces on the inferior portion and __________________ forces on the superior portion of the femoral neck. A. compressive, tensile B. tensile, compressive C. tensile, torsion D. torsion, tensile

A. compressive, tensile

Kinesiology is the study of

human movement

A soft foam pit is used for landing during the high jump. The foam pit cushions the landing of the jumper by:

increasing the displacement and time during the landing

The study of the time and space characteristics of movement is called

kinematics

all but one of the following joint actions takes place in the sagittal plane, Which action is not an example of a sagittal plane movement? A. Flexion B hyperextension C. lateral flexion D. plantar flexion

lateral flexion

The bio in biomechanics stand for

life

During an arm wrestling match, your opponent is winning. She is slowly pushing your arm down toward the table. The mechanical work you are doing against your opponent is:

negative

Which of the following is a vector quantity? A. Distance B. speed C. both distance and speed D. neither distance nor speed

neither distance nor speed

Muscle activation results in tension that: A. pulls the origin to the insertion. B. pulls both attachments about equally. C. pulls the insertion to the origin D. stabilizes both attachments.

pulls both attachments about equally

Kinetics is the branch of mechanics that:

quantifies the forces acting on a body

What describes the following law of motion: for every torque, there is an equal and opposite torque.

Newton's 3rd law

An unbelted victim in a car accident will continue to move in the same direction and with the same speed until the dashboard causes a change in motion. This best exemplifies:

Newton's first law of motion

When a dancer pushes off from the floor, the observed acceleration is less for the floor than for the dancer because:

the dancer has less inertia than the floor

Which of the following statements is false? A. the wrist is distal to the elbow joint B. the sternum is located medially within the frontal plane C. the knee is proximal to the hip joint D. the head is superior to the hips E. all of the above are true

the knee is proximal to the hip joint

The force developed during a contraction is the sum of A. the pulling forces that each actin cross bridge exerts on the myosin filament. B. the pulling forces that each actin cross bridge exerts on the sarcomere. C. the pulling forces that each myosin cross bridge exerts on the actin filament. D. the pulling forces that each myosin cross bridge exerts on the sarcomere. E. None of the above answers are correct

the pulling forces that each myosin cross bridge exerts on the actin filament.

The longitudinal axis is perpendicular to...

transverse plane

An example of an absolute angle would be: A. trunk lean in running B. knee angle in walking C. angle between the forearm and a golf club D. elbow angle in a biceps curl

trunk lean in running