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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 of physics by lay people. We present and discuss the results of two experiments wherein the extension of the chain, the height of release (experiment 1) and the material of the balls (experiment 2) were systematically varied in graphical depictions of the Newton's cradle. Participants had to estimate the height that the last ball in the chain would reach if a collision took place. The outcomes revealed a sophisticated cognitive model wherein the magnitude of the displacement of the target ball increased in direct proportion with the acceleration of the launcher and in inverse proportion with the number of balls in the chain. The results closely mimicked the predicted behavior of a Newton's cradle if the collisions were not perfectly elastic. This isomorphism shows that judgments of physical events are not detached from the environment, as one seldom sees a perfectly elastic collision, and it speaks unfavorably to the hypothesis that, in such tasks, people rely on simple heuristics.

In order to be treated quantitatively, subjective gains and losses (utilities/disutilities) must be psychologically measured. If legitimate comparisons are sought between them, measurement must be at least interval level, with a common unit. If comparisons of absolute magnitudes across gains and losses are further sought, as in standard definitions of loss aversion, a common known zero must be added to the common unit requirement. These measurement issues are typically glossed over in complex models of decision under risk. This paper illustrates how Functional Measurement (FM) affords ways of addressing them, given some conditions. It establishes a relative ratio model for the integration of gains and losses in a mixed gamble situation with independent outcome probabilities. It subsequently documents how this model yields functional estimates of gains and losses on a common unit scale with a known zero. The psychological significance of the found integration model is discussed, and some of its implications for measurement further explored across two studies. (Contains 6 figures and 1 table.)

Representational Momentum (RepMo) refers to the phenomenon that the vanishing position of a moving target is perceived as displaced ahead in the direction of movement. Originally taken to reflect a strict internalization of physical momentum, the finding that the target implied mass did not have an effect led to its subsequent reinterpretation as a second-order isomorphism between mental representations and principles of the physical world. However, very few studies have addressed the effects of mass on RepMo, and consistent replications of the null effect are lacking. The extent of motor engagement of the observers in RepMo tasks has, on the other hand, been suggested to determine the occurrence of the phenomenon; however, no systematic investigations were made of the degree to which it might modulate the effect of target mass. In the present work, we use Information Integration Theory to study the joint effects of different motor responses, target velocity and target mass on RepMo, and also of velocity and target mass on rating responses. Outcomes point not only to an effect of mass on RepMo, as to a differential effect of response modality on kinematic (e.g., velocity) and dynamic (e.g., mass) variables. Comparisons of patterns of mislocalisation with phenomenological ratings suggest that simplification of physical principles, rather than strict internalization or isomorphism per se, might underlie RepMo. (Contains 3 figures.)

The spatial memory for the last position occupied by a moving target is usually displaced forward in the direction of motion. Interpreted as a mental analogue of physical momentum, this phenomenon was coined "representational momentum" (RM). As momentum is given by the product of an object's velocity and mass, both these factors came to be under scrutiny in RM studies, the goal being to provide support for the internalization hypothesis. Although velocity was found to determine RM's magnitude, possible effects of mass were more elusive. Recently, an effect of target size on RM was reported, adding to previous findings that bigger targets were more mislocalized downward in the direction of gravity (via perceived heaviness and "representational gravity"; RG). The aim in the present research was to test that those outcomes reflect an internalization of momentum by excluding oculomotor factors. The results showed that an effect of target size, when it emerged, could be accounted for by a foveal bias such that bigger targets were more displaced toward gaze than were smaller ones. Specific contingencies between eye movements and target size seem to account for previous reports regarding the alleged effects of perceived mass on both RM and RG. This phenomenon seems furthermore to be modulated by the presence of other visual elements (fixation point) and the range of target velocities. These outcomes are taken as a rebuttal to the claim that cognitive analogues of mass or heaviness are responsible for previously reported effects of target size on both RM and RG.