What is light?

What is

light?

By Mike Cummings

​Light is made of vibrating electric and magnetic energy. This electromagnetic energy travels as a wave. These waves have frequency and amplitude. Light waves travel as transverse waves.

Multiple Select

Light energy moves as a wave made up of what kinds of energy?

• electric energy

• solar energy

• thermal energy

• magnetic energy

Multiple Choice

Light waves move as;

• longitudinal waves

• transverse waves

​Light energy travels with and without a medium, light can travel through the vacuum of space as well as travel through solids, liquids and gases.

Multiple Choice

Light is unable to travel through solids.

• True

• False

​Light in a vacuum travels about 186,000 miles/s, but does slow down as it travels through mediums such as solids, liquids and gases. The more dense the medium the slower light will travel.

Multiple Choice

Light energy moves slowest through;

• solids

• vacuums

• liquids

• gases

Multiple Choice

What is the speed of light?

• 186 miles per second

• 186,000 miles per minute

• 186 million miles per second

• 186,000 miles per second

Light is like a particle in that it travels in straight lines, these are called light rays. Light does not have mass like a particle of matter, but it does have momentum/force like a particle of matter.

​When light hits an object, it acts like a tiny particle. Light can change directions of atoms and other small particles. When particles of light hit matter it causes the matter to move creating kinetic energy. Kinetic energy creates friction which creates thermal energy. This is how objects get warm when the sunlight hits them. This is how you get sunburned and how blacktops get hot!

Multiple Choice

Light particles have the ability to move particles of matter.

• True

• False

Multiple Choice

Light energy can force particles of matter into creating thermal energy/heat.

• True

• False

​Particles of light are known as photons. A photon is a bundle of energy by which light travels. Energy within a photon are very small and we don't feel them, but over a period of time they can cause damage like sunburn.

Multiple Choice

The longer photons strike a surface the more damage they can cause.

• True

• False

​Photons in electromagnetic waves have frequency or speed. The faster the frequency the more energy they have and the more dangerous they can become.

Multiple Choice

Which of the following occurs as electromagnetic energy increases in frequency?

• They become more dangerous

• They move more slowly

• They are always safe

• They increase in pitch

Multiple Choice

Which color wave of light energy has the highest frequency?

• Green

• Aqua

• Orange

• Indigo

Multiple Choice

A particle of electromagnetic/light energy is known as;

• a proton

• an electron

• a photon

• a transverse wave