Yes, as long as m means the relativistic mass, i.e. [tex]\gamma m_0[/tex]. Notice that I calculated the acceleration, not the force. To be perfectly rigorous, you should actually work out the rate of change of 4-momentum.genneth, are you implying that Superman can get the ball going at the speed of light just by creating the force ( tension )
F = mc^2 / R ?
If not then why not? I would think a relativistic formula is needed.