Problem 1.344

With what velocity (relative to the reference frame $K$ ) did the clock move, if during the time interval $t=5.0 \mathrm{~s},$ measured by the clock of the frame $\vec{K},$ it became slow by $\Delta t=0.10 \mathrm{~s} ?$

v=c \sqrt{\left(2-\frac{\Delta t}{t}\right) \frac{\Delta t}{t}}=0.6 \cdot 10^{8} \mathrm{~m} / \mathrm{s}

Relativistic Mechanics