Test of Newton’s second law at small accelerations

We present the results of a test of Newton's second law for small accelerations. It is found that within experimental errors F=ma holds down to the lowest accelerations measurable with our apparatus, \ensuremath{\sim}3\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}9}$ cm/${\mathrm{s}}^{2}$.