Field Trip Notes
Guess who's selected to give an exhibition of a slam dunk during half-time of the big basketball game--Phoebe! The problem is, Phoebe can't jump high enough. 'If only gravity didn't pull on me!' she moans. Never one to be tied down, Ms. Frizzle sends them into space and turns the bus into a planet - with adjustable gravity! Basketball's a snap with low gravity, and a riot with no gravity at all. But when they end up with way too much gravity, things get really heavy!

What a Downer

Going Hands-On

Time: 20 minutes
Group Size: 4

Phoebe and her classmates find out that gravity pulls everything down. Your kids test whether gravity makes heavier things fall faster than lighter ones.

What You Need

For the class:

• Pencil tied to a string
• Scissors
• Copies of WHAT A DOWNER page

For each group: 

• 1 empty film canister filled with sand, pennies, or clay
• 2 pairs safety glasses for “Eyes” and “Ears”
• Stepladder (optional)

Talk About It

Hold up the string with the pencil suspended. Ask a volunteer to cut the string. Ask: What happened? Why did the pencil fall?

What To Do

1. Set up a dropping station for each group - stepladder, table edge, chair on table - the higher the better. Check that stations are sturdy.
2. Ask: Do heavy objects fall faster than lighter ones? How can we tell if one object falls faster than another? How will we know if the objects hit the ground at the same time? What senses can we use? (vision, hearing)
3. Give groups light and heavy film canisters to test. Ask: Does gravity pull equally on heavy and light objects?

Next Stop

If one kid throws a ball straight out, horizontal to the ground, and another drops a ball at the same time from the same height, will the balls hit the ground at the same time? (Yes. One may travel farther, but gravity pulls down on each equally, and they both fall at the same speed.) Ask: Is this difficult to judge with our senses? What could we use to improve our judgment?