Answer Key: Sights, Sounds and Gears_Unit level

Answer Key: Unit 5 Quiz

  1. A threshold is a cut-off value that divides a range of numbers into two groups: those above the threshold and those below.

  2. Some thresholds (like those for a light sensor) need to be calculated since they cannot be measured directly.  (i.e. if bright is 75 and dark is 25, the threshold, 50,  cannot be measured directly in View Mode, it must be calculated from the two values which can be measured).

  3. Since the threshold is 17 ((26+8)/2 = 17), the current reading of 16 is below the threshold and will be interpreted as dark.

  4. So the sound sensor is picks up less motor noise.

  5. 100 + 24 = 124
    124/2 = 62
    so the threshold should be set to 62

  6. Gear Ratio = 8/24 = 1/3, this is an example of gearing down, since 1/3 < 1.

  7. You want to gear up when you want more speed (at the expense of torque).  A dragster is an example of when you would want to gear up.

  8. You want to gear down when you want more torque (power).   Climbing a steep ramp or carrying a heavy load are examples of when you would want to gear down.

  9. Since the Wait-for-Light Block is waiting for bright (>50), then the floor must be dark.  Since the line is 10 above the threshold, then the dark floor must be 10 below the threshold, or 40. (Alternatively, 50 x 2 = 100; 100 – 60 = 40, so the threshold must be 40).

  10. The second block is waiting for quiet, not loud, so the tribot will stop as soon as the sound of the first clap dies down. (The second wait-for-sound block should be >50, and a <50 block needs to be added after the first Wait-For-Sound block).

  11. Raise the volume to 100% and check the Wait-For-Completion box

  12. The tribot will start moving when the light is turned on, run forward for 60 seconds, and then stop.  Ziffle needs to change the Move Block duration to unlimited.