KINS 382 LAB 19

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KINS 382 - LAB 19

• Review

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Question 1

• Choose the coefficient of restitution that is
  most plastic?
• a. .20
• b. .32
• c. .73
• Plastic objects do not rebound well

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Question 2

• T or F In the game of tennis a more elastic
  ball favors a more powerful player?
• True

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3, Definitions (Refer to your text or notes)

• Coefficient of restitution
• Moment arm (lever)
• Torque
• Momentum
• Impulse
• Line of action
• Fulcrum

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Question 4

• A force directed through a bodys axis of
  rotation produces
• a. no torque
• b. an increase in torque
• c. a decrease in torque
• d. a change in the moment arm

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Question 5

• T or F For a muscle lever to generate a
  constant joint torque during an exercise, it must
  produce more force as its moment arm decreases.
• True

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Question 6

• Which statement best describes a first class
  lever.
• a. The applied force and resistance are on the
  same side of the axis.
• b. Within the human body, the simultaneous
  action of agonist/antagonist muscle groups on
  opposite sides of a joint axis is analogous
• c. The applied force and the resistance are on
  opposite sides of the axis of rotation.
• d. b and c only
• e. none of the above

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Question 7

• T or F During an eccentric contraction, it is
  the muscle that supplies the resistance against
  the applied external force. During eccentric
  contractions, muscle and bone function as a
  second class lever.
• True

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Question 8

• A force can balance a larger resistance when the
• a. force moment arm is longer than the moment
  arm of resistance.
• b. moment arm of the force is shorter than the
  moment arm of the resistance.

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Question 9

• In many sports, maximizing the length of the
  effective moment arm for given propulsive force
  application can
• a. maximize the effect of the torque produced by
  muscle about a joint
• b. increase the force
• c. create more linear velocity
• d. a and c only
• e. all of the above

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Question 10

• T or F A change in the coefficient of
  restitution will be proportional to the force and
  the time over which the force is applied.
• False

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Question 11

• Write out the formula for momentum and impulse.
  Define the units
• Linear Momentum (P) P ?mv (kgm/s or Ns)
• Linear Impulse (J) J F?t (kgm/s
  or Ns)

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Question 12

• In an elastic situation, which statement/statement
  s are true?
• a. more control is provided because there is
  more contact time.
• b. the object deforms and returns to its
  original shape quickly.
• c. the contact time is decreased because very
  little energy is used in the deformation.
• d. b and c only
• e. all of the above

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Question 13

• Effective mass is the ability to transfer
  momentum from your body to an object.
• Identify the best statement(s) that apply to the
  effective mass theory
• a. during a collision the key is the ability to
  transfer momentum over a longer time period.
• b. in an impact situation lowering your center
  of gravity is critical.
• c. the ability to add the mass of the whole body
  is essential to golf.
• d. a and b
• e. none of the above

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Question 14

• T or F The conservation of linear momentum
  model (formula) implies there is no loss in the
  mechanical momentum of a system after a
  collision.
• True

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Conclusion