Chapter 3 Test Information

• Test format:
  • Part 1: 11 multiple choice / short answer.  One question will ask you to express 1m/s in mph.
• Part 2:  Problems
  • 2 "River" problems (2-4 parts each) -- Constant velocity in 2 dimensions.  Provide answers in terms of magnitude and direction (relative to some known direction). 
    • 1 orthogonal problem (two vectors will form a right triangle)
    • 1 non-orthogonal problem (often requires resolving components further into their individual x and y components, making a table wherein x and y components of component vectors are added to get the resultant x and y components, and finally re-combining x and y components to find the resultant magnitude and direction.)
    • You may be asked to find either a component or the resultant.  Students usually have more trouble finding a component.
  • 3 Projectile Problems (2-3 parts each) -- Kinematics in 2-D with acceleration due to gravity.
    • Symmetric problem
    • "half" of a symmetric problem
    • Asymmetric problem
• Sources for Similar Problems/Questions:  All of the unit 2 assignments and notes.
• Some Important Concepts:
  • Memorize -- 1m/s ≈ 2.24mph.
  • Add vectors head-to-tail
  • Determine the magnitude and direction of a vector (e.g. "degrees above +X" or "degrees north of west"), given its components
  • Find a missing vector using the concept of head-to tail addition
  • "River problems"
    • Identifying the resultant and component vectors
    • Solve for one of these: current or wind speed and/or direction (component), object speed and heading relative to water or air (component), actual object velocity relative to the earth (resultant)
    • Solve orthogonal (components aligned with x and/or y axes) and non-orthogonal river problems
  • Motion in terms of x and y...
    • Remember the independence of x and y components of projectile behavior
    • Resolving a vector into x and y components
    • Adding x and y vectors to get a magnitude and direction of a resultant
    • SohCahToa
    • Finding angles with inverse functions.

• Narrate what happens to v_x and v_y at all points during the flight of a projectile and explain why.
• Given a drawing of a projectile's trajectory, draw the projectile's v, v_x, and v_y vectors with appropriate lengths and directions, at any point in the diagram.
• Determine any of the following for a projectile:
  •  x or y displacement  (or height or distance)
  • time aloft
  • x or y velocity (initial or at any point in time)
  • speed and direction (angle)
• Provided formulas: same as last test, plus the range formula.