Velocity dependent forces varying as k(r^/r)(1−μr˙2+γrr¨) (such as Weber force), here called Weber-like forces, are examined
from the point of view of energy conservation and it is proved that they are
conservative if and only if γ=2μ. As a consequence, it is shown that
gravitational theories employing Weber-like forces cannot be conservative and
also yield both the precession of the perihelion of Mercury as well as the
gravitational deflection of light.Comment: latex, 11 pages, no figure