book+3+1.3

Book 3 1.3 1. When an object or wave hits a surface through which it cannot pass, it bounces back. 2. All waves obey law of reflection. 3.Incoming wave- a wave moving toward the surface at an angle 4. Reflected wave- wave that bounces off the surface at an angle 5. Normal- Dashed line- drawn perpendicular to the surface at the point where the incoming wave strikes the surface. 6. Angle of incidence- angle between incoming wave and the normal. 7. Angle of reflection- angle between the reflected wave and normal. 8. Law of Reflection- angle of incidence= angle of reflection 1. Bending of waves due to a change in speed. 2. Doesn't always occur when entering a new medium i.Only if at an angle ii.occurs because the 2 sides of the wave travel at different speeds iii.light can bend when it passes from water into air iv.white light separates into the colors you see in a rainbow 1.two types i.constructive ii.destructive 2.Constructive Interference- the interference that occurs when waves combine to make a wave with a larger amplitude. i.Crest of 2 waves overlap- make a higher crest. a.)amplitude increases 1.)sum of amplitude of 2 original crests ii.After they pass through each other, continue on as they were 3.Destructive Interference- two waves combine to make a wave with a smaller amplitude i.Subtract their energies ii.Crest meets Trough, if crest has larger amplitude, crest wins, if trough, has larger amplitude, trough wins. Same= cancel out. 1. Combined wave - incoming wave and reflected wave have the right frequency, they make a wave that appears standing still. 2. Destructive Interference produces points with amplitude of 0 i.Nodes- Points of 0 amplitude on a standing wave a.) always evenly spaced. 3. Constructive Interference the amplitude is greater than 0. i. Antinodes- points of maximum amplitude on a standing wave ii.Points of maximum energy on the wave iii.always occur halfway between 2 nodes 4.Resonance- increase in the amplitude of a vibration that occurs when external vibrations match an objects natural frequency i.Most objects have at least 1 natural frequency or vibration.
 * III. Interactions of Waves**
 * A. Reflection- Waves hit something and bounce back**
 * B. Refraction - when a wave enters a new medium at an angle, one side of the wave changes speed before the other side., causing the wave to bend.**
 * C. Diffraction- when a wave moves around a barrier or through an opening in a barrier, it bends and spreads out.**
 * D. Interference- the interaction between two waves that meet or overlap.**
 * E.Standing Waves- wave that appears to stand in one place, even though it is really 2 waves interfering as they pass through each other.**

1.True 2.False- Diffract 3.False- Refract or Bend 4. Diffraction- The bending and spreading out of waves around the edge of a barrier 5. Interference = interaction between waves that meet 6.Constructive Interference- interaction of 2 waves that results in a wave with a larger amplitude. 7.Destructive Interference- interaction of 2 waves that results in a wave with smaller amplitude 8.Standing Wave- a wave that appears to stay in one place 9.Resonance- increase in amplitude that occurs when external vibrations match an objects own natural frequency
 * __//QUIZ//__**

__//**Study**// **Guide**__ 7. Echo 8. combine to make a wave with a larger amplitude 14. diffraction 15. nodes 17. nodes 20. true 26. constructive interference; Destructive interference 27. see drawing/ get drawing