W3 & W5 Notes

W3- Reflection Reflection occurs when the wave does not pass into the new material, but is instead sent off in a new direction with the same amount of energy. When a light wave is reflected, it leaves the surface of the reflective material (water, a mirror, etc.) at the same angle at which it approached.

Shiny surfaces reflect light well. Polished metal and calm water are examples of surfaces that are good reflectors of light.

W3- Absorption Absorption occurs when an object takes in a wave's energy. Absorption is the opposite of reflection. Write a short summary of how humans see color. When objects absorb light energy, this energy is usually transformed into thermal energy. So as an object absorbs light energy, its temperature tends to increase because its thermal energy increases.

W3- Transmission Any light that is not reflected or absorbed by a medium is transmitted, or passed through it. Some materials transmit certain types of waves more readily than others. Refraction or bending occurs when waves pass from one medium into a new medium, such as when light travels from the air into water (or from water into air). Draw the demonstration.

This is caused by the fact that waves cannot travel as quickly in water as they can in the air.

W5- Seismic Waves Seismic waves occur any time energy is released in the Earth. Seismic waves can travel very long distances. There are two types of seismic waves, S-waves and P-waves. P-waves can travel through solids and liquids. These are the fastest and first to arrive. They are known as Primary waves. S-waves are transverse waves that can only travel through solids, these are the waves that are on the surface. They are slower than P-waves and are called Secondary waves.

P-waves cause very little damage. Scientists use these waves to determine the composition of the Earth’s interior. If an earthquake occurs in northern Canada, and seismologists in Florida study the S and P waves and the time it takes for them to arrive and how much of the waves arrive, they know how much of the interior of the Earth is solid or liquid.