On Sat, Jun 24, 2017 at 12:33 PM, ann sanfedele <ann...@nyc.rr.com> wrote:
> What is the difference in virtual weight of a pack (say, ten lbs) being > carried bys omeone walking on level ground and the same person carrying > the same pack up a flight of stairs? > > I'm sure I'm not using the corrrect terms here, I"m sure but I'm looking for > the as if.... related to the stress it puts on my body. > > Is it like I'm carrying 5 more lbs? 20 more lbs? etc I cannot answer that & am not sure anything meaningful can be calculated in those terms. But here's some stuff I do know in case it is helpful. The effort required to get up the stairs is in direct proportion to weight, so for example a 100-pound woman carrying a 10-pound pack works 10% harder than she would climbing the same stairs without the pack. The work done is that effort multiplied by the height it travels through, so for example hauling it up a 12' staircase is four times as much work as lifting it 3' to hang the bag at your hip. That work becomes potential energy which you get back going down, so for example if you drop the bag off a 12' balcony there is four times the lens-shattering energy you'd get dropping it from your hip. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
