If it approaches the boundary at an incident angle of 47o

Question

Solve the following problem given below:

Problem: An earthquake P wave traveling 8.1km/s strikes a boundary within the Earth between two kinds of material,

Part A- If it approaches the boundary at an incident angle of 47^o and the angle of refraction is 30^o, what is the speed in the second medium?

v=______?

Thanks in advance who solve the above problem, thanks in advance.