Wednesday, November 10, 2010

Towers and Parachutes

Week 3 introduces us to the famous legend of Galileo dropping objects from the Tower of Pisa.  We completed the student exploration guide of the ExploreLearing Free Fall Tower Gizmo.  Another free tower simulator, Galileo Drops the Ball, and many other science simulators are available from SEED.

Before starting the Gizmo I gave a simple demonstration.  I took a feather and a ball and asked which would fall faster; then I dropped a small toy and a large toy.  Some were surprised that the second set of objects hit the ground simultaneously.  Next I dropped a book and a sheet of paper, and they fell at different rates.  Finally, I placed the sheet of paper on top of the book and dropped them; they fell at the same rate.  That got them thinking about concepts that they could explore further with the Gizmo.

After learning about air resistance, terminal velocity, and vacuums, I gave the 3 physics groups a challenge.  They each needed to build an egg parachute that met two criteria.  First, the egg had to fall without breaking; second it had to fall more slowly than a rock dropped simultaneously.

Each of the three groups were all successful, and had very different designs.  The older boys used a large sheet of newsprint for the parachute and a thick cardboard cone to hold the egg.  It's a good thing it didn't rain that day...

The girls covered fabric with lamination, adding in straw stays for the parachute and along the strings; they had a foam cube for the harness, decorated with flowers.  It fell the fasted of the three, but still slower than the rock.

The younger boys used a trash bag for a parachute and a cut up egg carton for the harness, with a good amount of duct tape to hold it all together.

I gave them two weeks for construction.  The day of the drop was very windy.  All the kids (21 of them) gathered for the event.  You can see the videos of each parachute being dropped out a window, a team member dropping the parachute and an adult dropping a rock.

1 comment:

CherylinMA said...

Great experiment. I'm glad you captured it on video to share. I love videos in blogland.