This application simulates the simple pendulum experiment found in Physics teaching laboratories.

Use your finger (if on a mobile device) or the mouse arrow (in the desktop version) to:

• Pull and release the pendulum.
• Change between Time and Speed ​​modes.

Operating modes:

• Time Mode: Makes the stopwatch inform the time interval between the first two passes of the pendulum through the reference line (dashed line).
• Speed ​​Mode: Makes the device report the speed of the pendulum as it passes the reference line.

Buttons:

• Places the pendulum in the starting position.
• Sets the experimental noise level, which adds a margin of error to the period calculated by the timer.

This simulation works based on the EDO solution

The ODE is solved by the fourth order Runge-Kutta method. The acceleration due to gravity is assumed as $g = 9.8$ m/s$^2$ and the damping factor as $\gamma = 0.05$ s$^{-1}$.

Furthermore, there is the inclusion of an error $\alpha$ generated by a random variable. That is, each time the half period of the pendulum is calculated, or its speed, a value $\alpha$ is drawn within the interval $[-\epsilon, \epsilon]$ and added to the half-time or the speed reported on the device. $\epsilon$ is the amplitude of the noise. The value of $\alpha$ is made up of two parts: random error (~Gaussian distribution around the calculated value) and systematic error (offset added to the calculated value).

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