The sum of gravitational potential energy and kinetic energy is called mechanical energy. Use Figure 2 to find the mechanical energy
of an idealized pendulum at a variety of times in its cycle. Identify any pattern you
notice in the values of mechanical energy.

Explanation:

Mechanical energy = Gravitational potential energy + kinetic energy

Time            Gravitational potential energy        kinetic energy         Total ME

0                                    4                                                0                        4

2                                     2                                               2                        4

4                                     0                                               4                        4

6                                     2                                               2                        4

8                                     4                                               0                        4

and so on  

We see that total mechanical energy is always 4 which is constant .

So gravitational and kinetic energy changes cyclically but total mechanical energy is constant .

what does the table look like

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