3.1. Traction

Try these first

1. 1.

   Define traction in the context of solid mechanics.

   Hint

   Think of what forces act on the surfaces.

2. 2.

   What is torque?

   Hint

   Consider what happens when turning a handle.

3. 3.

   What does traction represent in solid mechanics?

   • Force per unit area
   • Mass per unit volume
   • Torque per unit length

   Hint

   Consider how forces are defined in terms of their contact surfaces.

4. 4.

   True or False: Torque due to body forces includes external loads only.

   • True
   • False

   Hint

   Remember the definition of body forces in terms of their distribution.

5. 5.

   Consider a cuboidal object where traction forces act on all faces. If the traction on the front face is known, describe how you would find the resultant torque on the object.

   Hint

   Think about how the distance of the applied force influences torque.

6. 6.

   A beam supports a load from two different points. Describe how you would calculate the effect of each point on the overall angular momentum of the system.

   Hint

   Be sure to consider how various distances from the pivot influence the overall rotational effect.