Construction
http://www.thesciencefair.com/Merchant2/graphics/00000001
The image on the left is a picture of Newton’s
Cradle. Although there is considerable controversy as to the inventor of this
device, not many would argue that the name Newton is appropriate for the title. The actual name “Newton’s Cradle” was coined by an English
actor named Simon Prebble in 1967. Around this time, his company began to
manufacture it as a mere desktop toy.
Various modifications and designs of this prototype have been devised; however, the concepts for its function are the same. Simple cradles consist of an odd number (5 in this case) of balls consisting of equal mass, shape, size, and uniformity. Smooth metal spheres with uniform density are ideal. These balls are suspended from a frame by two strings or lines of equal length. This two string method constricts the balls to move along a fixed curvilinear path. If calibrated correctly, the balls will barely touch each other at rest, and not deviate from the fixed path when utilized properly. The frame can be made out of almost anything; however, a sturdy material is desired to eliminate sway and warping due to stress.
Various modifications and designs of this prototype have been devised; however, the concepts for its function are the same. Simple cradles consist of an odd number (5 in this case) of balls consisting of equal mass, shape, size, and uniformity. Smooth metal spheres with uniform density are ideal. These balls are suspended from a frame by two strings or lines of equal length. This two string method constricts the balls to move along a fixed curvilinear path. If calibrated correctly, the balls will barely touch each other at rest, and not deviate from the fixed path when utilized properly. The frame can be made out of almost anything; however, a sturdy material is desired to eliminate sway and warping due to stress.
So What does Newton's cradle actually do?
As
stated before, the sole purpose of Newton’s Cradle is to be a classy toy, but many
people use them to demonstrate principles of physics (like the ones we are
going to look at). In the following sections, we will take a look at how this
device shows conservation of momentum and energy; but first, what does this
thing actually do. The answer is: a lot of cool stuff. The sole function is to
elevate a certain number of balls and allow them to crash back into the
remaining set to see the results. One or even all of the balls can be elevated
in either direction allowing many combinations of scenarios. Check out the video
below to see many of these “combinations” and how they react.