Week 1

• The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium.
• Sound waves are produced by vibrating or oscillating objects and are transmitted faster in solids than liquids and gases because solid particles are very close to one another.
• The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye.
• James Clerk Maxwell, a Scottish mathematician and physicist, discovered that the formation of electromagnetic waves is due to the oscillation of vibration of electric and magnetic fields.
• The wavelength and frequency of light are inversely proportional, just like in sound waves.
• The color components of visible light include violet, indigo, blue, green, yellow to orange, and red.
• This change in speed causes the bending of the components of light, a property of light known as refraction, at varying degrees upon crossing the boundary.
• The angle of incidence is equal to the angle of reflection.
• The amount of energy carried by an electromagnetic wave increases with frequency.
• Ultraviolet rays carry enough energy to kill cells of harmful microorganisms like bacteria. It can also harm human beings.
• Prolonged exposure to sunlight, especially from 10 A.M. to 2 P.M., can cause serious damage to the eyes and to the skin, such as severe sunburn and skin cancer called melanoma.
• X-rays and gamma rays carry energy that is great enough to make them highly penetrating.
• Scattering of light is the phenomenon in which light rays get deviated from its straight path on striking an obstacle like dust or gas molecules, water vapours etc.
• Red light is bent the least and violet the most.
• After a while, the absorbed light is emitted or released in different directions. This is called scattering of light. The color of the emitted light is the color of the light absorbed by the molecules.
• The light with higher frequency is the most absorbed and released by nitrogen and oxygen molecules in the atmosphere. Violet light has the highest frequency among the components of visible light.
• Sound waves are longitudinal waves, meaning they oscillate in the same direction as the direction of travel.
• What type of wave is a sound wave?

  Longitudinal wave
• Temperature, humidity, and altitude all affect the speed of sound in air. Generally, sound travels faster in warmer temperatures, higher humidity, and at lower altitudes.
• Frequency, which measures how many cycles of a wave occur per second, is measured in Hertz (Hz).
• When sound waves bounce off a surface, they undergo reflection. This phenomenon is similar to how light waves bounce off a mirror.
• Intensity is the term used to describe the perceived loudness of a sound. It is determined by the amplitude of the sound wave, with higher amplitudes corresponding to louder sounds.
• Mediums: Substances through which waves propagate, including solids, liquids, and gases. Each of it has specific properties affecting wave transmission.
• Wavelength is the distance between successive crests of a wave.
• Frequency is the number of complete cycles of a wave passing a point per unit time.
• Radio waves: Electromagnetic waves with the longest wavelengths, are used in communication, broadcasting, and radar.
• Microwaves: Electromagnetic waves with shorter wavelengths than radio waves, used in microwave ovens, satellite communication, and radar.
• Infrared: Electromagnetic waves with longer wavelengths than visible light, felt as heat, used in thermal imaging, remote controls, and infrared astronomy.
• Visible light: Electromagnetic waves visible to the human eye, comprising different colors with varying wavelengths.
• Ultraviolet: Electromagnetic waves with shorter wavelengths than visible light, responsible for sunburns, used in sterilization, and medical therapy.
• X-rays: Electromagnetic waves with shorter wavelengths than UV radiation, used in medical imaging and airport security.
• Gamma rays: Electromagnetic waves with the shortest wavelengths and highest energy, produced by radioactive decay and nuclear explosions.
• Refraction: Bending of waves as they pass from one medium to another, due to changes in speed.
• Dispersion: Separation of waves into different wavelengths as they pass through a medium, causing the rainbow effect in prisms.
• Reflection: Bouncing back of waves when they encounter a surface, maintaining the angle of incidence equal to the angle of reflection.
• Bouncing: Reflection of waves off surfaces at an angle equal to the incident angle, such as in billiards or acoustics.
• Diffraction: Bending of waves around obstacles or through narrow openings, causing them to spread out.
• Sound waves: Mechanical waves caused by vibrations, requiring a medium for transmission, used in communication, navigation, and music.
• Light waves: Electromagnetic waves that are visible to the human eye, enabling vision and various optical technologies.
• Scatter of light: Random redirection of light waves by small particles or irregularities in a medium, causing the sky to appear blue and clouds to appear white.