Mechanics:
Falling Coffee Filters

PIRA Class: 1K25.10

Purpose:
To demonstrate terminal velocity and how terminal velocity depends on mass.

Description: 

Drop a coffee filter and observe that it falls at nearly constant velocity.

1. Simultaneously drop one coffee filter from 1 m high and four nested coffee filters from 2 m high. Both sets of filters should reach the ground at the same time.

2. Challenge students to determine from what height to drop 2 coffee filters so that they reach the ground at the same time as a single filter.

NOTE: Make sure the set of four filters are nested tightly to keep their aerodynamics the same as the single filter. Terminal velocity goes as the square root of mass. This demo assumes both sets of coffee filters reach terminal velocity nearly instantly once released. The more filters you add the less accurate this assumption will be.

Equipment:
Coffee filters, 2 meter stick

Location:
Coffee filters are in the cabinet across from PHYS-102 (cabinet next to the tape and glue drawer), meter sticks are next to PHYS-102