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# action-reactiond

By Jim Robinson,2014-06-25 12:27
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action-reactiond

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Multiple Choice:

Directions: Beneath each of the following questions are four lettered phrases or sentences marked

(a), (b), (c), and (d), but ONLY ONE best fits the answer. Please decide which one is the

CLOSEST CORRECT answer. Then, write down the corresponding letter of the answer you have

chosen on the answer sheet.

1. A force of _____ is defined as the force that is capable of producing an acceleration of

21 cm/s to a mass of 1 g.

a. 1 g b. 1 dyne

c. 1 Newton d. 1 Pa

2. Which of the following quantities is NOT a scalar quantity?

a. A person’s body mass is 70 kg.

b. The walking distance between room A and room B is 400 meters.

c. The isokinetic strength of the quadriceps is 150 ft?lb clockwise.

d. The speed of a car is 90 kilometers per hour.

3. If a ball is thrown in the air, we recorded the motion of the ball using video camera at

rdthe sampling rate of 60 Hz. We found that the velocity of that ball is 2.0 m/s at the 43

ththsampling point, 3.0 m/s at the 44 sampling point, and 3.5 m/s at the 45 sampling point.

rdthThe averaged acceleration from the 43 to the 45 sampling point is _____.

22 a. (3.5-2.0) / (1/60) = 60 m/s b. (3.5+2.0) / (1/60) = 330 m/s

22 c. (3.5-2.0) / 2(1/60) = 45 m/s d. (3.5+2.0) / 2(1/60)= 165 m/s

4. Same as the Question #3, according to the finite difference technique, the rate of

thchange (acceleration) at the 44 sampling point is _____.

22 a. 3.0 / (1/60) = 180 m/s b. (3.0-2.0) / (1/60) = 60 m/s

22 c. (3.5-2.0) / 2(1/60) = 45 m/s d. (3.5+2.0) / 2(1/60) =165 m/s

5. The optoelectric motion analysis technique records the position of each reflective

markers and uses them to calculate the forces. This is one example of _____.

a. forward dynamics b. inverse dynamics

c. kinematic dynamics d. kinetic dynamics Apr 26, 2002 1

6. If the sampling rate is set at 60 Hz during signal collection, then it indicates that _____

samples are digitized per minute.

a. 30 b. 60

c. 90 d. 120

7. Which Newton’s laws of motion states that F=ma?

a. Law of gravitation b. Law of inertia

c. Low of action-reaction d. Law of acceleration

8. Which of the following statement is NOT TRUE?

a. The sampling theorem states that the signal must be sampled at a frequency at least

twice as high as the highest frequency present in the signal itself.

b. Most of the biosignals from daily human movement are contained in the lower 12-14

harmonics.

c. For smoothing the signals from any human daily movements, a high-pass filter is an

important tool to reduce aliasing errors.

d. The Nyquist frequency to record daily human movements is approximately 24-28 Hz.

9. An individual strengthens his quadriceps using a regular bicycle. Assume that the

knee joint travels from full extension to 90? of flexion, then to full extension during a

pedal cycle. What would be the angular speed of the knee joint as the pedal speed is

120?/sec?

a. 30?/sec b. 60?/sec

c. 120?/sec d. 240?/sec

10. Same as Question #9, but the individual uses an isokinetic bicycle. What would be

the angular speed of the knee joint as the pedal speed is 120?/sec?

a. 30?/sec b. 60?/sec

c. 120?/sec d. 240?/sec

2 11. If an object experiences an acceleration of 10 m/s, what would its velocity after 2 s?

Assume that it begins with an initial velocity of 10 m/s.

a. 10 + (10)(2) = 30 m/s b.10 - (10)(2) = -10 m/s

c. (10)(2) = 20 m/s d. (10)(10)(2) = 200 m/s

12.The applied science to define reliable physical measures of a person’s size and form is

called _____.

a. occupational biomechanics b. kinesiology Apr 26, 2002 2

c. anthropometry d. bioengineering

13. Which of the following sensors is suitable for soft or uneven surfaces?

a. Force platform b. Capacitor sensors

c. Piezoelectric sensors d. Strain gauzes

14. Suppose a person hangs with both of her legs keeps straight

horizontally. Suppose that the center of mass of her leg lies 0.4 m

directly out from the center of her hip joint. If one of her legs

weigh 30 kg, then the gravity acting on her one leg is ____.

a. (30)(9.8) = 294N b. (30)(9.8)(2) = 588N

c. (30)(9.8)(0.4) = 118N d. (30)(9.8)(0.4)(2) = 235N

15. Same condition as Question # 14, suppose that the iliopsoas muscle is the only muscle

holding her leg, and that its lever arm is 0.05 m. The muscle force to hold her leg

horizontally is _____.

a. (30)(9.8) / 0.05 = 5580N b. (30)(9.8)(2) / 0.05 = 1116N

c. (30)(9.8)(0.4) / 0.05 = 2360N d. (30)(9.8)(0.4)(2) = 4700N

16. Same condition with Question #14, the mechanical advantage of the lever system at the

hip joint is _____.

a. 30 / 0.4 = 75 b. 0.05 / 0.4 = 0.125

c. 30 / 0.05 = 600 d. 0.4 / 0.05 = 8

17. Concerning with equilibrium of an object, which of the following is NOT TRUE?

a. There is no more motion when an object is in equilibrium.

b. There is no net forces acting on this object when it is in equilibrium.

c. There is no acceleration when an object is in equilibrium

d. There is no rotation of the object.

18. _____ consist of electrically conducting plates that lie parallel to each other, separated

by a distance that is small compared to the linear dimensions of the plates.

a. Force platform b. Capacitor sensors

c. Piezoelectric sensors d. Strain gauzes

19. There are three types of lever in the world. The _____ is more common in the body.

a. first-class lever b. second-class lever

c. third-class lever d. It is hard to say which

Apr 26, 2002 3

20. The strength of a collagen fiber is defined as

a. the stress which the fiber can sustain before failure

b. the strain which the fiber can sustain before failure

c. the energy which the fiber can store before failure

d. all of the above

21. According to the distribution of the trabecular system, the compression fracture always

occurs at the _____ aspect of the vertebral body.

a. anterior b. posterior

c. superior d. inferior

22 . Which of the following postures would be less harmful(傷害) to the low back muscles

when you hold a heavy object in the front?

a. trunk bending forward with straight arms

b. trunk bending forward with hands close to the trunk

c. straight back with straight arms

d. straight back with hands close to the trunk

23. Under which type of graph can work be represented as the area?

a. force plot against time b. force plot against velocity

c. force plot against displacement d. force plot against harmonics

24. Concerning with harmonic analysis, which of the following is NOT TRUE?

a. It assumes that any biosignal can be expressed as the sum of proper amplitude of a

number of sine and cosine wave.

b. It transforms the signal from the frequency domain to the time domain.

c. The harmonics indicates the fundamental frequency at the frequency domain

d. The weighed coefficients adjust the amplitude of each harmonics.

25. A nail (骨釘) provides more fixation than a plate with screws when they are used for

fixation of bone fracture. During the early stage of the healing process of the fractured

site, callus formation would be expected more at the one with _____

a. nail fixation b. plate fixation with screws

c. screw fixation only d. plate only

26. By comparing the mechanical properties of bone and collagen fibers, which of the

following statements is NOT TRUE?

a. Both bone and collagen fibers increase in strength and stiffness with an increased

speed of loading Apr 26, 2002 4

b. Both bone and collagen fibers remodel in response to the mechanical demands placed

upon it.

c. Both bone and collagen fibers withstand high tensile loads more than compression

d. Both bone and collagen fibers behave like a viscoelastic material.

27. According to the graph below, which of the following statements is TRUE?

a. An decrease in cortical bone thickness in the elderly is noted.

b. The degenerative bone can only withstand half of the stress of the young bone.

c. The degenerative bone stores less energy to failure than the young bone.

d. The degenerative bone can withstand the same strain as the young bone.

Old stress Young

strain

28. During the early stage of the healing process of a fractured bone, callus formation at the

fracture site is important for increasing the strength of the bone because the callus area

has a higher ____ than the intact area.

a. bone resorption activity b. moment of inertia about the neutral axis

c. creep phenomenon d. ability of hysteresis energy stored

29. Consider that a skier who is falling forward, subjecting the tibia to a forward bending

moment. High tensile stress is produced on the posterior aspect of the tibia, and high

compressive stress acts on the anterior aspect. Contraction of the _____ muscle can

protect the tibia from failure in tension.

a. gastrocnemius b. tibialis anterior

c. quadricepts d. tibialis posterior

30. Which of the following statements about the anisotrophic phenomenon is TRUE?

a. Aniosotrophy indicates the phenomenon that the tissue exhibits different mechanical

properties when loaded in different speeds.

b. Only the bone tissue in human body presents the anisotrophic phenomenon. Apr 26, 2002 5

c. That the bone can tolerate more tensile stress in the horizontal direction than that in

the longitudinal direction is one kind of anisotrophic phenomenon.

d. Both stiffness and strength are greatest in the direction in which daily loads are most

commonly imposed.

31. Which of the following statements about ligament and tendon is NOT TRUE?

a. Both of ligament and tendon are dense connective tissues.

b. Both of ligament and tendon are composed of Type I collagen fibers.

c. The cells in both tendon and ligament are fibroblasts that produce fibers in the matrix.

d. The collagen fibers are organized in parallel bindles in both tendon and ligament.

32. On the stressstrain curve of the anterior cruciate ligament, a toe region is noted when

the load is applied. This toe region indicates that _____.

a. major failure of the ligament takes place

b. the ligament starts to have plastic behavior

c. the deformation of the ligament is irreversible (不可逆)

d. the wavy collagen fibers are straightened out

33. During the maturation (up to 20 years of age), which of the following signs may not

occur?

a. The number and quality of the cross-links within and between collagen fibers

increases.

b. The number and diameter of collagen fibers increases.

c. The laxity of the collagen fibers increases.

d. The tensile strength of the collagen fibers increases.

34. Tendons remodel in response to the mechanical demands placed on them. Which of

the following tendons may possibly have LESS tensile strength?

a. a tendon attached to a muscle with larger cross-section area as compared to that

attached to a muscle with smaller cross-section area

b. the tendon of a rat at the end of pregnancy as compared to that of the normal healthy rat

c. the Achilles tendon in a jogger (慢跑者) as compared to that in a sedentary person (

愛運動者)

d. a tendon with NSAID injection as compared to that with steroid injection

a 35. The creep phenomenon of a ligament indicates that _____.

a. the deformation increases quickly at first as the amount of the load remains constant

over a period of time Apr 26, 2002 6

b. the load decreases as time increases if the deformation keeps the same

d. the ultimate tensile strength of a ligament on the stress-strain curve

Apr 26, 2002 7

A

1 11 21 31 41 2 12 22 32 42 3 13 23 33 43 4 14 24 34 44 5 15 25 35 45 6 16 26 36 46 7 17 27 37 47 8 18 28 38 48 9 19 29 39 49 10 20 30 40 50

Apr 26, 2002 8

B

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Apr 26, 2002 9

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