Reaching higher goals by means of a reflecting wall. (23rd April 2015)

• Record Type: Journal Article
• Authors: Faella, O; De Luca, R
• Is Part Of: Physics education. Volume 50:Number 3(2015:May)
• Page Start: 352
• Page End: 357
• Publication Date: 2015-04-23
• Subjects: Physics -- Study and teaching (Secondary) -- Periodicals; 530.0712
• DOI: 10.1088/0031-9120/50/3/352
• Languages: English
• ISSNs: 0031-9120

Abstract

Abstract: A student realizes that a point particle that is able to rise at a given point P 0 at height H when launched vertically from the origin O of a Cartesian plane at a fixed initial speed V 0 cannot reach, by means of a direct shot from a small spring cannon, a point P positioned at the same height H and distance d from P 0, with 0 < d ≤ R, where R is the maximum horizontal distance attainable with an optimum throw at an angle of 45°. However, the student realizes that, in the absence of air resistance, conservation of energy does not prevent this possibility. Therefore, in order to reach point P, the student uses a perfectly reflecting surface, opportunely inclined with respect to the horizontal. The full story of how this is done will be narrated in this article.