Harvard Project Physics trajectory apparatus
Date: 1962-1972
Inventory Number: 2006-1-0080
Classification: Physics Demonstration
Dimensions:37.8 × 60.1 × 11.4 cm (14 7/8 × 23 11/16 × 4 1/2 in.)
DescriptionThis trajectory apparatus consists of two identical rectangular pieces of particle board, each fixed to a black stand with equal width. The particle boards are painted with a white, evenly spaced 29 by 29 grid. Every other column grid line and every other row grid line is slightly bolder such that larger blocks of four squares are highlighted.
Each particle board has a slit in the upper right had corner, and a second slit on the left hand side, just above half way down. The slits are just tilted towards the right of the vertical axis. There are two thin metal ramps that attach to the front of the particle board in the slits. As such, the ramps are highest on the lefthand side and descend to the right (each with a slight up-turn at the rightmost end, past the lowest point). One of the ramps is quite steep -- at about a 45 degree angle from the vertical axis. The other is more shallow -- at about a 70 degree angle from the vertical axis. Each ramp has a groove, allowing a 5/8" steel ball to roll down them.
Signedon face at top of each section: [crossed-ovals logo] DAMON
on face at top of each section: Project Physics
Inscribedon each label (one on each half): TRAJECTORY APPARATUS
FunctionThe trajectory apparatus is used to study the motion of falling bodies. A 5/8" steel ball is rolled down each ramp so that observers may compare the velocity, acceleration, and descent time of balls rolling down ramps of different inclinations.
The apparatus can be used in two ways. Either both ramps can be attached to the same particle board, or one ramp can be attached to each particle board permitting different opportunities for comparison. When the ramps are attached to the same particle board, their leftmost end points are the same permitting the observers to compare the arrival time of each ball.
Historical AttributesThis apparatus was designed to be used with Project Physics, a national physics curriculum developed in the 1960s. Project Physics materials included teaching aids, apparatus for student experiments, and books.
The Project Physics Course grew out of a Harvard University initiative to teach all students physics, not just those who would go on to careers in science. The course aimed to be a "humanistically oriented" introduction to "science at its best."
Damon Engineering produced and marketed a set of Project Physics laboratory equipment in coordination with the curricular work of Harvard physics professor Gerald Holton, California high school science teacher F. James Rutherford, and Harvard Graduate School of Education professor Fletcher G. Watson.
Primary SourcesThe Project Physics Collection of course books is archived online here.
Linda J. Greenhouse, "Gerald Holton: The Discovery That Scientists Are Also Philosophers Should Not Depend On Accidents," The Harvard Crimson, December 12, 1966; found online here.
ProvenanceScience Center Physics Lab