কোনটি সঠিক?

$\mathrm{m}=\sqrt{1+\dfrac{\mathrm{dl}}{\mathrm{c}^{2}}}$

$m=\dfrac{m_{0}}{\sqrt{1-\frac{v^{2}}{c^{2}}}}$

$m=m_{0} \sqrt{1-\dfrac{v^{2}}{c^{2}}}$

$m=m_{o} \sqrt{1+\dfrac{v^{2}}{c^{2}}}$