Single Pendulum

Statement of the problem

This is a problem of single pendulum where we use a rigid bar instead of a particle. The pin-joint is presumed to be frictionless and thus the only force acting on the rod is gravity. What we try to find out are the angle, angular velocity, and angular acceleration of the mass center of the rod.

Exercises

Specify a initial angle of the rod which is measured from the horizontal line. By either moving the slider or entering a number in the box, then run the program. Notice that the angle should be between and
Stop the program when the rod finishes its motion of at least two complete cycles, check out both the angular velocity and acceleration.
Observe the x and y component of the reaction force.
Go to File and Export the Meter Data to a file then using the Excel to plot the results, comparing them with the numerical results by the Matlab program.
reset the program back to its original state.

Think Twice

Let's ignore the numerical error, can you explain the motion by the principle of work and energy? Does the reaction force have contribution to the system/rod? Remember that the principle of work and energy can be stated as

eqnarray50

and the kinetic energy T for the rigid body (rod) consists of two parts,i.e. translational and rotational energy;

where is the moment of inertia at the mass center.

Back To First Page

Back To Example Table