On 22.02.2008 23:41, Ben Goetter wrote: > >> hours...using gravity! :-) (Consider the XO using > >> about 2 watts...) > > There seems little danger of this mechanism being useful on Earth for > the XO-1. A 30kg human child who can move her own mass a meter > vertically (via a series of pulleys, or perhaps just climbing stairs > with a buddy riding piggyback etc.)
If the child has a mass of 30 kg, why should he/she carry anything else piggyback one meter upwards to gain 300 J of potential gravitational energy (assuming g=10 m/s^2)? The child already gets that potential enery if it climbs the stairs alone. > can invoke only 300J of potential > gravitational energy, or enough to let an XO sleep for two and a half > minutes assuming a 100% efficient conversion from gravitational to > electrical potential. > Regards, Carl-Daniel -- http://www.hailfinger.org/ _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
