Conservation of Mechanical Energy with Cobra DigiMotion

Principle

Energy is encountered everywhere in everyday life. When an object falls or a pendulum swings, potential energy and kinetic energy are continuously converted into one another. From a physical perspective, the sum of kinetic and potential energy remains constant in a closed system, provided that no friction or external influences act on it. Energy is not lost but merely transformed from one form into another. During free fall in the Earth's gravitational field, an object initially possesses potential energy. As it falls, this energy is continuously converted into kinetic energy. Using the MotionBoard, the fall of a MotionDot can be recorded precisely in real time, allowing the development of position and velocity over time to be analyzed and the energy conversion process to be investigated quantitatively.

Tasks

Release a MotionDot using an electromagnet and let it fall along the MotionBoard.
Record the position data in real time using the LABsense app.
Determine the velocity from the position–time graph.
Calculate the kinetic and potential energy from the measured data.
Repeat the experiment several times and calculate average values.
Compare the energy curves and discuss possible deviations from the ideal model.

Learning objective

Learners experimentally investigate the conservation of mechanical energy and recognize that in a closed system the sum of kinetic and potential energy remains constant. They analyze measurement data, derive velocities from position data, and apply these findings to energy-related considerations. In addition, they deepen their understanding of velocity, acceleration, and energy conversion in a gravitational field. Through the graphical evaluation of measurement curves, they strengthen their mathematical skills, particularly in interpreting graphs and identifying relationships.

Benefits