Practice Quiz 7

Choose the best answer

  1. State Newton's second law.
    1. An object will remain at rest or move in a
      straight line with a costant speed unless
      acted upon by a net force.
    2. Any two objects in the universe attract each
      other with a force directly proportional to
      the product of their masses and inversely
      proportional to the square of the distance
      separating them.
    3. The force acting on an object is directly
      proportional to the acceleration produced by
      the force.
    4. The force acting on an object is inversely
      proportional to the acceleration produced by
      the force.
    5. For every reaction, there is an equal but
      opposite reaction.
    Answer: C

  2. Which of the following situations can be
    explained by Newton's second law?
    1. When the force acting on an object is doubled,
      its acceleration is doubled.
    2. When a driver applies the breaks suddenly, his
      body jerks forward.
    3. When a man fires a gun, his body jerks backwards.
    4. A feather falling in a straight line with a
      constant speed.
    5. A man walking forward while pushing on the
      ground backwards.
    Answer: A

  3. Weight of an object is
    1. measured in terms of kilograms
    2. a measure of the amount of matter an object has.
    3. a measure of the gravitational force exerted on
      the object by the massive object in the
      vicinity of the object.
    4. the same with the mass of the object.
    5. the same on different planets.
    Answer: C

  4. An object has a mass of 45.945 kg. Calculate
    its acceleration when acted upon by a
    force of 100 N.
    1. 1.939 m ⁄ s 2
    2. 1.577 m ⁄ s 2
    3. 0.839 m ⁄ s 2
    4. 3.612 m ⁄ s 2
    5. 2.177 m ⁄ s 2
    Answer: E

  5. Calculate the acceleration of an object of
    weight 60 N when subjected to a force of 15.435 N.
    1. 0.356 m ⁄ s 2
    2. 2.521 m ⁄ s 2
    3. 4.689 m ⁄ s 2
    4. 2.179 m ⁄ s 2
    5. 3.139 m ⁄ s 2
    Answer: B

  6. A force that causes an acceleration of 5 m ⁄ s 2
    on an object of mass 28.333 kg is acting on a
    46 kg object. Calculate the acceleration of the 46 kg object.
    1. 3.08 m ⁄ s 2
    2. 2.301 m ⁄ s 2
    3. 0.488 m ⁄ s 2
    4. 4.97 m ⁄ s 2
    5. 3.864 m ⁄ s 2
    Answer: A

  7. The angle formed between force of friction and
    normal force is
    1. 0 degree
    2. 45 degree
    3. 90 degree
    4. 180 degree
    5. 60 degree
    Answer: C

  8. Which of the following is not a correct
    statement?
    1. Coefficient of friction is equal to the ratio
      of normal force to force of friction.
    2. If normal frorce is doubled, force of friction
      will be doubled.
    3. Coefficient of friction is unit less.
    4. Static coefficient of friction is greater than
      kinetic coefficient of friction
    5. The force required to just get an object slding
      is bigger than the force required to slide
      it once it has started sliding.
    Answer: A

  9. An object of mass 24.443 kg is sliding on a horizontal
    surface. Calculate the normal force exerted by
    the surface on the object.
    1. 239.541 N
    2. 106.77 N
    3. 321.698 N
    4. 132.9 N
    5. 360.068 N
    Answer: A

  10. An object of mass 36.445 kg is sliding on a horizontal
    surface with a uniform speed. The coefficient
    of kinetic fiction of the surfaces is 0.4. Calculate
    the force of friction exerted by the surface on the object.
    1. 185.616 N
    2. 78.263 N
    3. 142.864 N
    4. 267.931 N
    5. 224.201 N
    Answer: C

  11. An object of mass 30.555 kg is being pulled by a
    horizontal force of 250 N on a horizontal force.
    The coefficient of kinetic friction between
    the object and the surface is 0.15. Calculate the
    acceleration of the object.
    1. 10.97 m ⁄ s 2
    2. 12.125 m ⁄ s 2
    3. 2.019 m ⁄ s 2
    4. 5.055 m ⁄ s 2
    5. 6.712 m ⁄ s 2
    Answer: E