23 Feb, 2013
Loop the loop
PRESENTATION: A v-shape metallic profile is used to build a ramp with a loop in the middle. Neglecting the effect of friction, a steel ball is let to fall from the necessary height to complete the loop. The energy dissipated by friction makes this height value to be slightly higher than the value obtained according to the law of conservation of mechanical energy. The effect of the inertia moment of the falling body can be also analyzed.
- Could an athlete run a 3-m radius “loop-the-loop”, Angelo Armenti, Phys. Teach. 19, 624 (1981)
INTRODUCTION: “Energy cannot be created or destroyed, but it can be transformed”. The Law of Conservation of Energy is the cornerstone of Physics. In daily life, if we consider friction to be negligible, mechanic energy is also conserved. Examples of this are roller coasters, where this law plays a key role, a good example.
OBJECTIVE: To make the ball complete a loop to prove the Law of Conservation of Energy by considering friction to be negligible.
MATERIALS: a steel ball, an aluminum sheet, some aluminum paper, a wooden board, a stand (a ladder in this case), some nails.
SETUP: The loop end is fixed to the wooden board with (using) nails and the beginning of the ramp is sustained by the stand. Use the aluminium foil paper to reinforce the rail to ensure that the ball will not fall out of its trajectory.
CONCEPTS: potential energy, kinetic energy, energy conservation, gravitational field.
- Tipler P.A. Física. Barcelona: Reverté, 2010.
- De Juana J.M., Física General, Pearson, 2009.
- Serway R.A y J.W.Jewett. Física, Thomson-Paraninfo, 2010.
STUDENTS 2012-2013: Iván Díaz, Alejandro Espiño, Alba Souto, Victor lago García
LINK pdf STUDENTS: