Problem 1.379

A particle of rest mass \(m_{0}\) moves along the \(x\) axis of the frame \(K\) in accordance with the law \(x=\sqrt{a^{2}+c^{2} t^{2}}\), where \(a\) is a constant, \(c\) is the velocity of light, and \(t\) is time. Find the force acting on the particle in this reference frame.