Reflection and Refraction Bouncing Wave The medium for

Reflection and Refraction

Bouncing Wave ] The medium for waves is not always uniform. • Extreme case is for a collision with a barrier A single pulse is reflected back in the opposite direction.

Open Ended ] The medium may end in air. • Extreme case the end is loose and completely free A single pulse is reflected back in the same direction.

Mixed Media ] The medium may change. • A thin rope attached to a thick rope Part of the pulse is reflected but part is transmitted.

Ray Tracing ] Waves can be seen as sets of parallel lines moving forward. • Wave fronts • May be curved ] A ray follows a point of successive wave crests. • Perpendicular to front • Straight until a barrier is reached

Perfect Mirror ] Larger waves also interact with barriers. We can follow a line perpendicular to the wave front. • These are called rays ] A reflected ray has the same angle after reflection. • Angle qi = qr

Rough Shoulder ] A car approaches a sandy shoulder from pavement. • The wheels that hit the shoulder slow down • An angle causes the car to turn into the shoulder

Refraction ] As a wave changes its medium the speed changes, and so does its wavelength.

Snell’s Law ] ] For plane waves the angles are related to the speeds in the two media. This is called Snell’s Law next