Day 151: Throwing Things

Wednesday, 12 April 2017

While two of my classes took a unit test today, the third got sent outside to throw things  in the air — for projectile motion. I asked them to show evidence as to whether or not the sportsball they chose was in equilibrium while flying through the air, considering horizontal and vertical equilibrium separately. Here they are filming their throws:

IMG_20170412_142547

and here’s one group’s graph:

IMG_20170412_143522

After 15 minutes of throwing, filming, and video-analyzing, we circled up and discussed. The evidence went something like this: See this position-time graph above? Because the vertical motion (in blue) shows changing velocity, it must have non-zero net force. And because the horizontal motion (in red) shows constant velocity, it must have zero net force.

Side note: I default to video analysis whenever possible, so my kids are good at it by now. We did this entire activity in about 20 minutes, including the discussion.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s