During a ripple tank experiment, plane wavefronts reach a plane surface. Which row correctly describes the waves after reflection from the surface?
- Aspeed of waves: larger; wavelength $\lambda$: shorter
- Bspeed of waves: smaller; wavelength $\lambda$: shorter
- Cspeed of waves: the same; wavelength $\lambda$: longer
- Dspeed of waves: the same; wavelength $\lambda$: the same