ACUTUS MENS – Semester 2
AM #1
- Define wave. A periodic disturbance in a solid, liquid, or gas as energy is transmitted through a medium.
- Give 3 examples of media. Solid, Liquid, Gas
- What 2 things can waves travel through? Matter and Space
- What does a wave carry? Energy
AM#2
- What kind of waves require a medium? Electromagnetic Waves
- What kind of waves do NOT require a medium? Mechanical Waves
- What do we call waves that are produced by a combination of longitudinal and transverse waves? Surface Waves
- What is amplitude? Why is it significant? Height of the wave from the rest point; Larger amplitude = more energy
- What is frequency? Why is it significant? The number of waves produced in a given amount of time; as frequency increases, wavelength decreases and vice versa
AM #3
- How do we calculate wave speed? Wave speed (γ) = wavelength (λ) X frequency (f)
- What is the relationship between frequency and wavelength? As frequency increases, wavelength decreases and vice versa
- Differentiate between reflection, refraction, and diffraction.Reflection – the bouncing back of a wave; Refraction – the bending of a wave as it changes medium; Diffraction – bending of a wave around a corner or through a hole
- What is interference? Explain the two types of interference. When waves overlap. Constructive – waves overlap and builds (gets louder or brighter); Destructive – waves overlap and collapse (dimmer light or creates noise)
- What is a standing wave? Give an example. Pattern of vibration that stimulates a wave that is standing still (looks like it is standing still); car wheels spinning while driving
- Explain resonance. Give an example. When 2 objects naturally vibrate at the same frequency; sound produced by one causes the other to vibrate; loud radio bass causes mirrors to vibrate
AM#4
- What kind of wave is a sound wave? Mechanical and Longitudinal
- How does sound travel? By vibration
- In what direction do sound waves travel? All directions.
- Define a medium. An object through which a wave travels (solid, liquid, gas).
AM#5
- What are the 3 sections of the ear? Outer, Middle, Inner
- What are the 3 bones in the middle ear called? Hammer, Anvil, Stirrup
- What is responsible for transmitting sound electrically to the brain? Cochlea
- Predict what may have happened if a person has lost their hearing (answers will vary).
- What are the 3 kinds of instruments? Strings, Winds, Percussion
AM #6
- What is pitch? How is it related to frequency? How low or high a sound seems to be; high pitch = high frequency and low pitch = low frequency
- What do we call sounds that have a frequency too high to hear? ultrasonic
- What happens when a jet breaks the sound barrier? Build up of constructive interference; as the jet reaches the sound barrier, the constructive waves move quickly to the back of the jet resulting in rapidly moving particles that create a sound know as a “sonic boom”
- Describe the Doppler effect . Change in frequency of a wave when the source or observer is in motion (like severe weather warning sirens).
- Define noise. Random mix of frequencies (depends on listener).
AM #7
- Define loudness. What is the unit used to measure loudness? How well a sound can be heard; decibel
- How are amplitude and frequency related? High amplitude = high frequency and vice versa
- What is used to change a longitudinal sound wave into a transverse wave? Oscilloscope
- What is an echo? Reflected sound wave
- What surface reflects an echo the best? Flat, smooth surface
AM #8
- What is an electronic echo called? Radar
- What do we call the process of using sound to locate an object? echolocation
- What medical procedure allows us to “see” inside the body without surgery? Ultrasonography (ultrasound)
- Define a sonic boom. The crashing of constructive waves built up as a jet passes through the sound barrier. The particles crash together all at once resulting the very loud sound.
- What are the 2 kinds of standing waves? Fundamental and resonant frequencies
AM #9
- Define sound quality. Blending of pitches through interference.
- Define noise. Random mix of frequencies (depends on listener).
- What is an electromagnetic wave? A wave that is made of electric and magnetic fields that vibrate – does not require a medium.
- Define radiation. Transfer of energy by electromagnetic waves.
- What is the electromagnetic spectrum?All the frequencies or wavelengths of electromagnetic radiation; divided based on wavelength
- List the waves of the electromagnetic spectrum in order from longest to shortest. Radio Waves – longest; used in radio signals and TV signals; Microwaves – used in microwave ovens , radar, cell phones, and satellites; Infrared – heat detection, night vision goggles; Visible Light – very narrow band (the Rainbow – ROYGBIV); Ultraviolet – produced by sun, causes sunburn, kills bacteria; X-Rays – used in detection of broken bones and security devices; Gamma Rays – used to kill bacteria on food and in treatment of specific types of cancers.
- Differentiate between the 2 kinds of reflection. Regular – reflection seen when using a flat, plane mirror; Diffuse – reflection seen when using a contoured mirror (like a fun house mirror).
AM#10
- Compare absorption to scattering. Absorption – light particles are absorbed by the object (very little light is reflected); Scattering – light is largely reflected (like a disco ball)
- What is refraction? Give an example. Bending of a wave as it changes medium; a light beam travelling through a piece of paper (gas to solid, then back to gas)
- Define diffraction. Bending of light around corners or through a hole (under a door, etc.)
- What are the three things light can do? Reflect, Absorb, and Transmit
- What are the 3 kinds of objects and how do they relate to light?Opaque – absorbs part of light and reflects the rest; Transparent – transmits light; Translucent– absorbs part and scatters the rest.
- When we look at an object, what color do we see? The color of light that is reflected.
- What happens to the other colors? They are absorbed.
AM #11
- What are the three primary colors of light? Red, Blue, and Green
- When the 3 primary colors of light are combined in equal amounts, what do they create? White light
- What is pigment? An opaque substance that reflects and absorbs light.
- What are the three primary pigment colors? Cyan, Magenta, Yellow
- When the three primary pigments are added together in equal amounts, what is the result? Black
- Compare the primary colors of light to the primary colors of pigments.Light – Red, Green, and Blue – combine to make white light; Pigments – Cyan, Magenta, Yellow – combine to make black
- Draw a convex and concave lens/mirror. Concave - Convex -
AM #12
- What is a plane mirror? Flat mirror
- Which type of lens magnifies? convex
- Which type of lens make images appear fine and crisp? concave
- What are the 2 most common vision problems? Nearsightedness and farsightedness
- What is the function of the following parts of the eye: retina, pupil, lens, optic nerve, cornea, iris?Retina–back of eye, contains rods (black and white) and cones (color); Pupil – black part of eye where light passes through; Lens – convex lens that refracts light; Optic Nerve – flips image right side up and sends signals to brain; Cornea – provides shape to the eye; Iris – colored portion of the eye.
- Name 3 ways light affects your life (answers will vary). Cameras, Telescopes, Lasers, etc.
AM#13
- What are the properties of a magnet?Material that attracts ferromagnetic material.
- What are the opposite ends of a magnet called? poles
- What is magnetic force? The push or pull exerted by a magnet.
- Explain how a magnetic field works. The area around a magnet where t he magnetic force is effective.
- How can a magnet lose its’ magnetic alignment? (How can you destroy a magnetic field?) Striking it very hard, dropping from a very high altitude, heating it.
- How can you create a magnet? Rub a ferromagnetic material on a strong magnet – only temporary.
- How is the Earth like a magnet? Has a magnetic field, made of spinning electrons
- Explain the relationship between north and south poles on a magnet. Like poles repel, opposite poles attract.
AM#14
- How does a compass work? Magnetized needle that aligns itself with the magnetic pull of the Earth (pointing North).
- What happens when you break a magnet? You get 2 new (less powerful) magnets.
- Give an example of a magnetic light show. Aurora Borealis (Northern Lights)
- What is generated when charges flow through a wire? Electric current
- What is the unit used to express the amount of charge that flows through a wire? Amperes (amps)
- What does an electric current produce? What happens if the current reverses? A magnetic field; the magnetic field reverses as well.
- What can electrical current flow through? A circuit.
AM #15
- Define an electric circuit. The closed path through which charges can flow.
- What are the 3 components to a circuit? Energy source, wires, load.
- Compare a conductor to an insulator and give an example of each.Conductor moves current easily – the electrons are loosely bound. Copper is an excellent example. Insulator prevents current from moving – the electrons are tightly bound. Rubber is an excellent example.
- What happens when you flip a switch? The circuit closes and the electrons are free to move.
- What is resistance? The opposition to the flow of a charge.
- What object is used to help control resistance? Resistor
- Give an example of how resistance is very useful in our lives. Prevents electrical fires. Your toaster would blow up with out resistance!
- Compare a series and a parallel circuit. Use drawings if necessary.Series connects loads in only one path. Parallel connects to loads on both sides providing multiple paths for current to flow.
AM #16
- What are the characteristics of a superconductor? No electrical resistance, very efficient, strongly repels magnets, must be kept very cool.
- How does an electric motor function? Changes electrical energy into mechanical energy.
- What is a galvanometer? A device, run by an electromagnet that detects current.
- What is an armature? A coil or loop in a motor that provides movement for a charge.
- What is the function of a commutator? Reverses the direction of a charge.
- How does an electric generator work? Changes mechanical energy to electrical energy.
AM#17
- What function does a transformer serve? Speed up or slows down current as it flows through wires.
- What is ferromagnetic material and how is it used in electromagnets? Material made from iron or nickel that is highly attracted to magnets. It provides the core to an electromagnet.
- How does an electromagnet function? Has 2 poles that act like switches; when attached to an energy source the ferromagnetic material becomes magnetized.
- What is the coil called that is used in an electromagnet? solenoid
- How can you increase or decrease the power/strength of an electromagnet? Increase or Decrease the number of coils in the solenoid or add a stronger/weaker ferromagnetic material.
- Give an example of an electromagnet. A crane in a junkyard, but all of your technological devices contain electromagnets.
AM #18
- What does the law of electric charges state? Like charges repel, opposites attract.
- How are an electric force and an electric field related? An electric force creates an electric field.
- Describe 3 ways to charge an object. Give examples.Friction – rubbing balloon on your head and sticking it to the wall (wiping electrons); Conduction – building up electrons on your feet and then touching a metal doorknob (charge transfers by direct contact); Induction – charge happens when an object is exposed to another charge (Van Degraff Generator)
- What kind of device can detect a charge? Electroscope
- Explain static electricity and electric discharge. Charge at rest on an object; touching a conducting object (doorknob) transfers the charge (discharge).
- In relation to electricity, what does it mean to be grounded? Electric current to transferred to the ground via wires.
- Compare AC to DC.AC – Alternating Current – moves in 2 directions; DC - Direct Current – moves in 1 direction.
AM #19
- What is voltage and how it related to energy? Voltage is the amount of energy needed to push a charge through a wire
- What unit is used to express voltage? volts
- Why do batteries vary in voltage? The vary in need and size.
- How does resistance factor in with insulators and conductors? Conductors have low resistance; Insulators have low resistance.
- If you wanted maximum voltage what kind of wire would you want? Does temperature play a part? Thick, short wires in a cool setting is ideal!
- What does Ohm’s Law state? The ratio of voltage to current is constant and referred to as Resistance.
- What unit to we use to measure resistance? An Ohm - Ω
AM #20
- Define electric power. What unit is used to express electric power? The rate at which electrical energy is changed into other forms of energy. (Plug in a lamp and it changes into light and thermal energy).
- One kilowatt (kW) equals how many watts?1000
- Give examples of series and parallel circuits. Series – old Christmas tree lights and burglar alarms; Parallel – circuitry in a home or building
- What is a fuse? Small, thin piece of metal that expands and opens a circuit to prevent the flow of charge.
- How are circuit breakers used in our homes? To prevent electrical fires; a safety net.