> Michel Jullian wrote: >> Harry Veeder wrote: >>> However, concerning the tubular lifter, I would argue that the >>> elevated tube when the lifter is _accelerating upwards is evidence that the >>> _internal forces_ don't add up to zero. >> >> The elevated tube is merely a "deformation" due to internal forces.
I think it means the weight of the elevated tube has essentially disappeared (although the tube's inertia remains unchanged). In other words, the lifter's ascending weight is less than its stationary weight. Harry
