Phonebook / Envelope (1C20.18)
Location: 16-2C
Concept/Purpose: Uniform Acceleration
Procedure/Explanation: Air resistance is demonstrated by dropping a phonebook and an
envelope (or a piece of paper, feather, coffee filter) at the same time from the same height. Note
that the envelope takes longer to reach the floor. Now place the envelope on top of the phone
book, and drop the phone book; this shows that with the air resistance of the envelope being
reduced, the envelope and phone book fall at the same rate.