Torque Questions

Consider the following three situations, where a force is applied to a revolving door that rotates about its center:
A - a force F is applied perpendicular to the door halfway between the center and one end.
B - a force F is applied perpendicular to the door at one end.
C - a force 2F is applied perpendicular to the door halfway between the center and one end.

Rank these situations based on the magnitude of the torque experienced by the door, from largest to smallest.

  1. C>A>B
  2. C>B>A
  3. C>A=B
  4. B>C>A
  5. B>A>C
  6. B>A=C
  7. None of the above















Consider the following three situations, where a force is applied to a door that is free to rotate about its center. In each case the magnitude of the force is the same and the force is applied to the door halfway between the center and one end.
A - the force is directed perpendicular to the door.
B - the angle between the force and the door is 30°.
C - the angle between the force and the door is also 30°.

Rank these situations based on the magnitude of the torque experienced by the door, from largest to smallest.

  1. C>A>B
  2. C>B>A
  3. C>A=B
  4. A>C>B
  5. A>B>C
  6. A>B=C
  7. None of the above















Consider the following three situations, where one or two forces are applied to a door that is free to rotate about its center.
A - the force F is directed perpendicular to the door and is applied halfway between the center and one end.
B - one force F is directed perpendicular to the door and is applied halfway between the center and one end; another force F in the opposite direction is applied at the end of the door.
C - one force F is directed perpendicular to the door and is applied halfway between the center and one end; another force F in the opposite direction is applied at the far end of the door.

Rank these situations based on the magnitude of the torque experienced by the door, from largest to smallest.

  1. C>A>B
  2. C>B>A
  3. C>A=B
  4. B>C>A
  5. B>A>C
  6. B>A=C
  7. None of the above