Author note: "_" means subscript, and "^" means superscript in the following. Any tips on how to write equations in PF posts will be appreciated. The Lorentz transformation of acceleration components, from IRF K’ to K, can be accessed via Google on the Internet. The transformation of a_y^' contains two terms, say A+B. If it is stipulated that a_y^'=0, then A=-B, or a_y=-(vu_y a_x/c^2)/(1-(vu_x)⁄c^2 ). Clearly a_y can be nonzero in certain cases. Consequently we have the purely kinematic result that a_y^' may be zero, whereas a_y is nonzero. What are the implications of this curious result?