Question Number 82596 by peter frank last updated on 22/Feb/20
Commented by mr W last updated on 23/Feb/20
$$\left({a}\right) \\ $$$${i}\:{think}\:{the}\:{beam}\:{will}\:{stay}\:{in}\:{water}. \\ $$$$\left({b}\right) \\ $$$${the}\:{beam}\:{will}\:{be}\:{partially}\:{reflected} \\ $$$${and}\:{partially}\:{go}\:{into}\:{the}\:{water} \\ $$$$\left({see}\:{green}\:{lines}\right). \\ $$
Commented by mr W last updated on 23/Feb/20
Commented by mr W last updated on 23/Feb/20
$$\frac{\mathrm{sin}\:\alpha}{\mathrm{sin}\:\mathrm{49}°}=\frac{\mathrm{sin}\:\mathrm{51}°}{\mathrm{sin}\:\mathrm{90}°} \\ $$$$\Rightarrow\alpha=\mathrm{35}.\mathrm{9}°<\mathrm{49}° \\ $$
Commented by peter frank last updated on 23/Feb/20
$${thank}\:{you} \\ $$