Newton's cradle, a device consisting of a chain of steel balls suspended in alignment, has been used extensively in physics teaching to demonstrate the principles of conservation of momentum and kinetic energy in elastic collisions. The apparent simplicity of the device allows one to test commonly hold views regarding the intuitive understanding…

Examines whether kindergarteners, second-graders, fourth-graders, and adults can extract relative weight information from observing collisions and lifting events, and if they can judge whether or not collisions are momentum-conserving. Subjects saw either videotapes of events or sequences of static images; younger children appeared to be…