stem exam

• Electromagnetic Spectrum


  Includes all types of electromagnetic radiation, which vary in wavelength and frequency
• Types of Electromagnetic Radiation

  • Radio Waves
  • Microwaves
  • Infrared
  • Visible Light
  • Ultraviolet
  • X-Rays
  • Gamma Rays
• Radio Waves


  • Longest wavelengths and lowest frequencies, used for radio/TV broadcasts and communication systems
• Microwaves


  • Shorter wavelengths than radio waves, used in microwave ovens and radar
• Infrared


  • Associated with heat, used in remote controls and thermal imaging
• Visible Light


  • Small part of the spectrum that humans can see, includes all colors from violet to red
• Ultraviolet


  • Higher energy than visible light, can cause sunburn, used in black lights and sterilization
• 1. Rays


  • Very high energy, can penetrate most substances, used in medical imaging
• Gamma Rays


  • Shortest wavelengths and highest energies, produced by radioactive atoms and nuclear explosions, used in cancer treatment
• Sources of Light


  • Natural Sources (Sun, stars, fireflies, chemical reactions)
  • Artificial Sources (incandescent bulbs, fluorescent lights, LEDs, lasers)
• Forces


  • Gravitational Force
  • Electromagnetic Force
  • Strong Nuclear Force
  • Weak Nuclear Force
• Gravitational Force


  • Force of attraction between two masses, keeps planets in orbit and causes objects to fall
• Electromagnetic Force


  • Acts between charged particles, includes electric and magnetic forces
• Strong Nuclear Force


  • Force that holds protons and neutrons together in the nucleus, very strong but acts over short distances
• Weak Nuclear Force


  • Responsible for radioactive decay processes like beta decay
• Interactions


  • Reflection
  • Refraction
  • Diffraction
  • Absorption
• Reflection


  Light bouncing off a surface, forming images
• Refraction


  Bending of light when passing from one medium to another with different density
• Diffraction


  Spreading of light waves as they pass through a narrow opening or around obstacles
• Absorption


  Light absorbed by a material and converted into other forms of energy, like heat
• Kinetic Energy (KE)


  Energy an object possesses due to its motion, given by KE = 1/2mv^2
• Types of Potential Energy (PE)

  • Gravitational PE
  • Elastic PE
• Gravitational PE


  Energy due to an object's height above the ground, given by PE = mgh
• Elastic PE


  Energy stored in stretched or compressed springs
• Reflection (optics)


  Light bouncing off a surface, angle of incidence equals angle of reflection
• Refraction (optics)


  Bending of light as it enters a different medium, described by Snell's Law
• Lenses and Mirrors


  • Concave Mirrors/Lenses (converge light rays)
  • Convex Mirrors/Lenses (diverge light rays)
• Real Image


  Formed when light rays converge at a point, can be projected onto a screen, usually inverted
• Virtual Image


  Formed when light rays appear to diverge from a point, cannot be projected, usually upright
• Scalar Quantities


  • Mass
  • Speed
  • Distance
  • Energy
• Scalar Quantity


  Has only magnitude (size or amount) and no direction
• Vector Quantities


  • Velocity
  • Force
  • Displacement
  • Acceleration
• Vector Quantity


  Has both magnitude and direction
• Vector Operations


  1. Addition (combine head-to-tail)

  2. Subtraction (reverse direction and add)

  3. Dot Product (scalar product)

  4. Cross Product (vector product)