A Basic Acceleration Example Problem and Understanding Acceleration Direction
(9:53)
This video starts with a simple acceleration problem and then addresses a commonly held misconception that a negative acceleration always means you are slowing down.  I do this by way of examples.  Kate (my wife) drove the Prius with a camera suction cupped to the window and videoed me riding my bike several times.  In the end I ended up with four different examples on the screen at once and 25 different video layers to describe it all.  I am really proud about how well it worked.  Enjoy.

Content Times:
0:26 Reading the problem
0:40 Seeing the problem
1:14 Translating the words to Physics
1:54 Solving the problem
3:50 Why is the number on the bike positive?
4:48 How can the bike be speeding up if the acceleration is negative?
5:50 Comparing velocity and acceleration directions
7:28 All four bike examples on the screen at the same time
7:53 Why isn't there a direction on our answer?
8:51 Outtakes or how the bike riding was filmed
  • この Flipping Physics のビデオに日本語字幕がつきました。小竹知紀さん，協力ありがとう！