tolng dengan caranya

[tex]L=L0 \sqrt{1- \frac{ v^{2} }{ c^{2} } } \\ \frac{3}{4} L=L\sqrt{1- \frac{ v^{2} }{ c^{2} } } \\ \frac{9}{16}= 1- \frac{ v^{2} }{ c^{2} } \\ \frac{ v^{2} }{ c^{2} }= \frac{16}{16} - \frac{9}{16}= \frac{7}{16} \\ \frac{v}{c} = \frac{ \sqrt{7} }{4} \\ v= \frac{ \sqrt{7} }{4}c[/tex]

[tex]\ell =\ell_0 \sqrt{ 1-\frac{v^2}{c^2} } \\ \frac{3}{4}L=L \sqrt{ 1-\frac{v^2}{c^2} } \\ \\( \frac{3}{4})^2=( \sqrt{ 1-\frac{v^2}{c^2} } )^2 \\ \\ \frac{9}{16}= 1-\frac{v^2}{c^2} \\ \\ \frac{v^2}{c^2} =1-\frac{9}{16} \\ \\ \frac{v^2}{c^2}= \frac{7}{16} \\ \\ \frac{v}{c}= \sqrt{ \frac{7}{16} } ===>>> v= \sqrt{ \frac{7}{16} }} ~~c= \frac{1}{4} \sqrt{7}~c [/tex]