Scratch Motion Challenges

  1. Download motionproject from Scratch. Select See Inside. Select File -> Download to your computer.
  2. Find project on your computer & open.
  3. Find the operator to round the speed variable to a whole number.
  4. Add another vehicle.
  5. Add code to second vehicle to calculate for time instead of speed:
    • you'll need new variables for speed, distance, time and start position (hint: Data)
    • you'll need a new equation (hint: Operators)
  6. Input the same distance for each and race them. What did you observe?
  7. Add a finish line sprite. Can you get it to show up at the right distance? (hint: you'll have to play around aligning the sprite's center)
  8. Switch to a "winner" background. How can you use Sensing with a Broadcast to declare the winner?
  9. Try using another Motion command to get vehicles moving at the correct speed. What are the challenges in doing this?
  10. Try simulating acceleration with code. What are the challenges in doing this?
    final velocity - starting velocity
    --------------------------------------- === average acceleration
    time it takes to change velocity
  11. Create an animation where a ball (or something) moves 1 step. Change framerate. Observe how changing framerate changes perceived speed of ball. Number of steps (distance) is held constant, number of frames are held constant:1 step XX frames---------- * --------------- === XX steps/sec, which is distance over time, which is speed, the magic quantity.frame second