Project 13, Part A: You spin me right round

Last time on post-apocalypse now: Your group of scientists have begun work on putting together an alternative power generator based on a merry-go-round ride from a playground. Suddenly a wormhole opens in the middle of the Thunderdome and four strangers clad in 2010's clothing emerge. They relay that they have been trapped for years in a place called the Marvel universe by someone named Korath and that they eventually escaped. Time does not flow at the same rate in the Marvel universe, and so they are shocked to find themselves in a post-apocalyptic Earth. They quickly develop a plan to rewrite history by combining the generator your scientists have been working on with exotic technology they stole from the Marvel universe to create a time machine that can send a small metallic item back in time. But first you need enough energy to power the time machine.

The merry-go-round ride has one bar moving from the centre of the ride to a point at the edge of the ride. You also have available to you seven 5kg weights with some straps. The uniform density disk that comprises the ride is 300kg and has a radius of 2.5m. Your team which is working on the roundabout consists of 4 members. You are informed by the lead scientist of the new arrivals “Flo Rida” that the ride needs to achieve an energy of either 1036 Joules or 6500 Joules in order to generate enough electricity to send what you have decided is a paperclip back in time.

But as plans are put in place the Thunderdome comes under attack from boar tigers. Luckily as a defensive precaution, a pit has been dug to surround the roundabout and been set on fire (boar-tigers are afraid of fire).

Powering the time machine to 1036 Joules will send the paperclip back to the original satellite launch and make critical machinery fail and stop the apocalypse. Powering the time machine to 6500 Joules will send the paper clip back to a time in which you knew Carver was driving his car before an accident and will cause the vehicle to explode preventing Carver from launching the satellite or any future satellites. The future (or the past) is in your hands. Choose wisely.