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In this study, we found that the optimum take-off angle for a long jumper may be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. The prediction method was evaluated using video measurements of three experienced male long jumpers who performed maximum-effort jumps over a wide range of take-off angles. To produce low take-off angles the athletes used a long and fast run-up, whereas higher take-off angles were produced using a progressively shorter and slower run-up. For all three athletes, the take-off speed decreased and the take-off height increased as the athlete jumped with a higher take-off angle. The calculated optimum take-off angles were in good agreement with the athletes' competition take-off angles. 相似文献
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This paper assesses the causes and consequences of recent American efforts to configure the research university as an engine of economic and social change. Drawing upon interviews and strategic plans, the paper describes recent policies to encourage interdisciplinary creativity, in a context of increasing income from private gifts and endowments.This revised version was published online in May 2005 with corrections to the text on page 26. 相似文献
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Changes are being made in the content of presentday electrical engineering curriculums which require a fresh, modern outlook with regard to techniques pertaining to problem assignments and laboratory projects. Course content is being upgraded and broadened in the direction of a fundamental analytical approach. The recent revision of the electrical engineering curriculum at The Pennsylvania State University, University Park, includes liberal use of an ac network calculator in all electrical engineering options, which are outlined in this paper. The uniqueness of the ac network calculator at the University is that it is used exclusively for educational purposes, especially in the Department of Electrical Engineering. This paper discusses the "when, where, and how" of the utilization of this facility in the electrical engineering curriculum. 相似文献
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