Interview Questions

These are all questions that I have asked or been asked during an interview process. They appeal to me because they demonstrate analytical method and they are non-obvious. They all have that "uh...wait a minute" moment in them.

• Why does a bicycle or motorcycle turn when leaned over?
  Compare this phenomenon with the centering action of a flat belt on a crowned pulley.
  
  
• In an inflated underwater habitat, open at the bottom, how does the stress on the structure and skin of the habitat vary with the depth of the habitat under water?
  
  
• What is the difference in stresses in the habitat:
  1. When anchored underwater and inflated, versus:
  2. When it is suspended upside down in air and filled with water?
  
  
• How do you inspect a conical feature?
  
  
• Draw a right triangle of height h and base b. Draw the largest possible inscribed circle. At the top of that circle, draw a tangent line parallel to base b to create a triangle smaller than but similar to the original triangle. Within that smaller similar triangle, again draw the largest possible inscribed circle, and again draw a tangent parallel to base b. Repeat for an infinite series of similar triangles and inscribed circles. What is the sum of the circumferences of the infinite series of inscribed circles?
  
  
• What are the dimensional units of compliance?
  
  
• Discuss the role of perpendicular forces in a trigger mechanism.
  
  
• Where does the energy come from to speed up the water passing through a nozzle?
  
  
• How do you determine that a piece of magnetic recording tape is flat and straight edged?
  
  
• Guide rails may be straightened by attaching them to x,z mounts and adjusting them as necessary to bring the rail into acceptable straightness where x and z are perpendicular to the axis of the rail. Sketch an x,z mount that achieves the necessary adjustments, without slides, and with only one adjustment screw for each axis of motion.
  
  
• How might you improve the designs of draft horse harness, control lines on a sail boat, or a ten-speed derailleur? What are the pertinent constraints on these designs?
  
  
• A whip cracks because its tip speed exceeds the speed of sound, creating a sonic boom. Why does the tip accelerate to that speed?
  
  
• To the millifoot, what was the standard stride of a Roman Legionnaire?