Students:
1.developed the relationship between the orientation of the wavefronts and the direction of propagation of the periodic waves;
2.discussed why the orientation of wavefronts changes as a wave enters a medium of different depth (i.e.,different speed)and how it affects the direction of propagation;
3.recognized boundary conditions: wavefronts must be continuous at the boundary;
4.drew ray and wavefront diagrams for a specific situation, identified angles of incidence and refraction ,and discussed how a change in affects .