Lever systems and mechanical advantage: แบบฝึกหัด

• a.

  A swimmer performing a bicep curl with a resistance band during dry-land training.

• b.

  A basketball player performing plantar-flexion at the ankle to jump for a rebound.

• c.

  A tennis player performing an overhead serve involving extension at the elbow.

• d.

  A footballer kicking a ball involving extension at the knee joint.

• a.

  \(7.0\); Extension of the elbow during a tricep dip.

• b.

  \(0.14\); Extension of the neck when looking up.

• c.

  \(0.14\); Flexion of the elbow during a bicep curl.

• d.

  \(7.0\); Plantar-flexion at the ankle during a calf raise.

• a.

  Fulcrum - Effort - Load; provides high mechanical advantage for strength.

• b.

  Load - Fulcrum - Effort; provides a balance between speed and strength.

• c.

  Fulcrum - Load - Effort; provides a high mechanical advantage (ability to move a large load with relatively little effort).

• d.

  Effort - Fulcrum - Load; provides high speed and range of movement.

• a.

  It provides maximum stability for the joint during impact.

• b.

  It reduces the amount of oxygen required by the agonist muscle.

• c.

  It allows the player to lift heavier weights with less muscular force.

• d.

  It allows for increased speed and range of motion at the end of the lever.

• a.

  Exactly 1.0.

• b.

  Less than 1.0 (Mechanical Disadvantage).

• c.

  Greater than 1.0 (Mechanical Advantage).

• d.

  It depends on the weight of the head.

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