While it’s impossible to design a perpetual motion machine, that is, a machine that keeps moving forever, come up with ways to keep some type of periodic motion going for a very long time. explain the limits on perpetual motion. discuss what slows down a machine and how you might minimize those effects for at least one specific form of periodic motion, such as the motion of a spring or pendulum, or circular motion. come up with an inventive solution!

It would be hard so many factors play a role in this angle kinetic potential energy gravity positioning height weight etc.to keep something as described moving as long as possible you'd have to build it heavily enough to balance out the momentum at each climax of the swing to balance with the gravitational pull of the earth core.I'd use a material such as copper for the variable.Also the weight distribution on the variables base plays a role.Take all the into account and experiment for a while!maybe one day you could find the right proportions in every role for kinetic potential gravitational momentum and weight to keep it going forever. As said alotta factors play a huge role in this experiment  

The answer is d, you can easily test a theory! hope i you : )