Light

• What type of radiation is light classified as?

  Light is a type of electromagnetic radiation.
• How does light travel compared to sound waves?


  Light travels as a transverse wave and does not need a medium to pass through.
• What is the speed of light in air?

  The speed of light in air is very close to $300,000,000 \text{ m/s}$.
• How does the speed of light compare to the speed of sound?

  The speed of light is nearly a million times faster than the speed of sound.
• What is the approximate speed of sound?

  The speed of sound is approximately $340 \text{ m/s}$.
• What does the large difference in speed between light and sound explain?

  It explains why we see lightning before we hear thunder.
• How far does light travel in one second?

  In one second, light travels a distance of $300,000,000 \text{ m}$.
• What is the relationship between light and the speed of sound in terms of distance traveled?

  Light travels about seven and a half times around the world in one second.
• What is the maximum speed at which anything can travel?


  Nothing can travel faster than the speed of light.
• What are the main differences between light waves and sound waves?

  • Type of wave: Light waves are transverse; sound waves are longitudinal.
  • Travel through matter: Light can travel through transparent or translucent materials; sound can travel through solids, liquids, and gases.
  • Travel through a vacuum: Light can; sound cannot.
  • Detection: Light is detected by eyes and sensors; sound is detected by ears and microphones.
  • Speed: Light travels at $300,000,000 \text{ m/s}$; sound travels at $340 \text{ m/s}$.
• How does light travel in terms of direction?

  Light travels in a straight line.
• What is a ray diagram used for?

  A ray diagram shows how light travels and what happens when it reaches a surface.
• What is a pinhole camera?

  A pinhole camera consists of a box or tube with a translucent screen at one end and a tiny hole at the other end.
• What happens to the image formed by a pinhole camera?

  The image is upside down and smaller than the object.
• What is light?


  Light is a form of energy.
• How does a pinhole camera demonstrate the principle of light traveling in straight lines?

  Light enters through the pinhole and forms an image on the screen, showing that light travels in straight lines.
• How do we perceive light?

  We perceive light through our eyes, which detect the light around us.
• What causes shadows to form?

  Shadows are formed when an opaque object blocks light from reaching a surface.
• What happens when light enters our eyes?

  Our brain interprets the light into images we can see.
• What is a solar eclipse?

  A solar eclipse occurs when a new Moon passes directly between the Sun and the Earth, blocking the Sun's rays.
• What does the light from the Sun look like?

  The light from the Sun looks white but is a combination of many different colors.
• What are the two parts of a shadow during a solar eclipse?

  The total shadow is called the umbra, and the partial shadow is called the penumbra.
• How can we see the different colors of sunlight?

  We can see the different colors of sunlight by splitting it using a glass prism.
• What happens during a total solar eclipse?

  The Moon casts the darkest part of its shadow, the umbra, on Earth, covering the entire disk of the Sun.
• What is a rainbow and how is it formed?

  A rainbow is formed when sunlight is split by water droplets in the air.
• When will the next total solar eclipse occur in the UK?

  The next total solar eclipse in the UK will be on 23 September 2090.
• What is light classified as?

  Light is a form of electromagnetic radiation.
• What safety measures should be taken when viewing a solar eclipse?

  Never look directly at the Sun; use special glasses or a pinhole camera to view the eclipse safely.
• What is a luminous object?

  A luminous object is one that emits its own light.
• From where does the Earth receive its light?

  The Earth gets its light from the Sun.
• How does light travel?

  Light travels as transverse waves.
• Give examples of luminous objects.

  Examples of luminous objects include the Sun, stars, fire, and light bulbs.
• Can light travel through a vacuum?

  Yes, light can travel through a vacuum.
• What is a non-luminous object?

  A non-luminous object does not emit its own light and is seen because it reflects light from luminous objects.
• How long does it take for the Sun's light to reach the Earth?

  It takes about eight minutes for the Sun’s light to reach us.
• Give examples of non-luminous objects.

  Examples of non-luminous objects include the Moon, planets, and walls.
• What is the speed of light?

  The speed of light is approximately $300,000,000 \text{ m/s}$.
• How does a mirror reflect light?

  A mirror reflects light by having a thin reflecting layer behind a piece of glass.
• What are objects that do not allow light to pass through called?

  Opaque objects.
• What type of mirrors are most everyday mirrors?

  Most everyday mirrors are flat and are called plane mirrors.