Mechanical energy conservation investigation using photodiode sensor based on Arduino Uno

Mechanical energy (ME) is the sum of potential energy (U) and kinetic energy (K) and associated with the motion and position of an object. The values of ME will always perpetually if the force is constant, while the value of K and U depend on the object position. This study aims to design an apparatus for investigation of the mechanical energy conservation experiment through free fall events using three point photodiode-sensor measurements based on Arduino Uno platform. A prototype is made from PVC cylinder of 100 mm diameter and a height of 100 cm, holed with a height of 100 cm, holed with surface pattern to minimize air friction inside the tube and the acceleration of falling objects is equivalent to the acceleration of the earth’s gravity, which is 9.8067 ms⁻². Three photodiode sensors are installed straight on the prototype belt to enable the receiver collects light directly from the transmitter while the second sensor is movable up and down to latch the ball travel time, time between interrupts is then measured as well as U and K on an interface. The experiment shows that the decrease in U is proportional to the increase in ME, where the U of objects decreases by 0.0099 Joule every 100 mm distance while K of objects increases by 0.0098 Joule. In the middle of the cylinder with the height of falling objects is 50 cm, then U = K, so the ME value has remained constant.