Re: Riddles with a Prize, by Mantus Anchors
Force has to be...
Which radically assumes the spring can in fact absorb and return that force. In practice, the spring may be too weak to store that much energy, resulting in a total failure to launch the box.
Rather than assuming the physical properties of a spring, I maintain the box is located at a LaGrange point and it will plummet to a death in a gravity well before the box ever leaps up after Jack. A much simpler assumption.