[tex]Dane:\\\alpha = 60^{o}\\sin60^{o} = 0,866\\\beta = 35^{o}\\sin35^{o} = 0,574\\v_1 = c = 3\cdot10^{8} \ \frac{m}{s}\\Szukane:\\v_2 = ?\\\\\\\frac{sin\alpha}{sin\beta} = \frac{v_1}{v_2}\\\\sin\alpha \cdot v_2 = sin\beta \cdot v_1 \ \ /:sin\alpha\\\\v_2 = \frac{sin\beta}{\sin\alpha}\cdot v_1\\\\v_2 = \frac{0,574}{0,866}\cdot3\cdot10^{8} \ \frac{m}{s}\\\\\boxed{v_2 \approx2\cdot10^{8} \ \frac{m}{s}}[/tex]
