Problem Graphic


Louis the Lamp is tired of his lonely existence up in the attic and attempts to escape through a trap door in the floor. He must determine which of the supports he should remove so that the door will open.

What is known:

  • The trap door is supported by a hinge and a bearing with a circular shaft on one side.
  • The other side is supported by a sliding bolt, which is equivalent to a bearing with a square shaft.

Hinge Diagram


What type of reaction forces and moments does each of the supports exert on the trap door?


  • Analyze the conventional methods by which rigid bodies are held stationary, or are held together.
  • Determine the type of forces and moments that these supports exert on a rigid body in reaction to externally applied loads.
  • There is not enough data to determine the exact magnitude of each reaction. Only determine the type of reaction.
Practice Homework and Test problems now available in the 'Eng Statics' mobile app
Includes over 500 problems with complete detailed solutions.
Available now at the Google Play Store and Apple App Store.