Potential Energy
Kinetic Energy
Waves: Light
Waves: Sound
Digital vs. Analog
100
Define Potential energy and give one classroom example
Book on a shelf, poster hanging on wall
100
What is kinetic energy? Name one factor that affects the amount of kinetic energy an object has.
Kinetic energy is the energy of motion. Factors: Mass or Speed.
100
Is light a transverse or longitudinal wave? How do you know?
Transverse. The vibrations move perpendicular (up and down) to the direction the wave travels.
100
Does sound need a medium to travel? Give a brief explanation.
Yes. Sound travels by bumping particles into one another; without matter (atoms), the energy cannot move.
100
Give a simple definition for analog signal and a simple definition for digital signal.
Analog: A continuous signal that varies smoothly. Digital: A signal that uses discrete values (usually 0s and 1s).
200
Which two factors determine the gravitational potential energy of an object near Earth’s surface? Write the relationship in words and name the SI unit.
Mass and Height. Relationship: The more mass or height an object has, the more GPE it stores. Unit: Joule (J).
200
True or false: If two objects have the same speed but different masses, they have the same kinetic energy. Explain your answer.
False. Because Kinetic Energy depends on both mass and speed, the object with the larger mass will have more energy even at the same speed.
200
Name three things that can happen to light when it meets a material.
Reflection (bouncing), Absorption (soaking in), or Refraction (bending).
200
Identify whether sound is a longitudinal or transverse wave and describe what vibrates in a sound wave.
Longitudinal wave. The particles of the medium (like air molecules) vibrate back and forth in the same direction the wave travels.
200
List one advantage of digital signals over analog signals when sending information over long distances.
Digital signals are more reliable because they are easier to "clean up" if they pick up noise or interference.
300
A book is on a shelf 2 meters high. Explain qualitatively how its potential energy changes if the book is moved to a shelf 5 meters high.
The potential energy increases. Since GPE is directly proportional to height, moving it higher stores more energy.
300
The kinetic energy of an object depends on its speed in a specific way. Describe how kinetic energy changes when speed doubles.
If the speed doubles, the kinetic energy quadruples (increases by 4 times).
300
Explain why a straw in a glass of water looks bent at the surface, using the idea of light changing direction between materials.
This is called refraction. Light changes speed as it moves from water to air, causing the light rays to bend.
300
If two sound waves have the same amplitude but different frequencies, how will our perception of pitch and loudness compare?
They will have the same loudness, but the one with the higher frequency will have a higher pitch.
300
Describe how an analog audio wave differs visually from a digital representation of the same audio.
An analog wave is a smooth, continuous curve. A digital signal looks like a "staircase" or a series of pulses because it is made of sampled, discrete values.
400
Describe elastic potential energy and give an example involving a spring or rubber band.
Energy stored when an object is compressed or stretched. Example: Energy stored in a stretched rubber band before it is released.
400
A cyclist doubles their speed while mass stays the same. By what factor does their kinetic energy change? Explain using the relationship between kinetic energy, mass, and speed.
It changes by a factor of 4. The formula is KE =1/2mv2 Since speed (v) is squared, 22 = 4.
400
Describe one way brightness and one way color of light are related to wave properties. Use the terms amplitude and frequency.
Amplitude determines brightness (higher amplitude = brighter). Frequency determines color (different frequencies = different colors).
400
Explain how the speed of sound changes with the medium (e.g., air vs. water) and why.
Sound travels faster in water (liquids/solids) than in air. This is because particles are packed closer together, allowing them to collide and pass energy more quickly.
400
Explain why small amounts of noise affect analog signals more noticeably than digital signals.
In analog, every change in the wave is part of the information. In digital, the receiver only needs to know if the signal is "High" or "Low" (1 or 0), so it can ignore small wobbles caused by noise.
500
Explain how the arrangement of objects interacting at a distance (like two magnets) can store different amounts of potential energy. Include what must change to increase the stored energy.
Energy is stored in the magnetic field. To increase it, you must move the magnets in a way that "fights" the force (e.g., pulling apart two attracting magnets or pushing together two repelling magnets).
500
Describe a real-world situation where kinetic energy is converted into thermal energy and explain the energy transfer.
Using car brakes or rubbing your hands together. Friction converts the energy of motion into heat (thermal energy).
500
Explain why light can travel through empty space but sound cannot. Include a short comparison of the kinds of waves involved.
Light is an electromagnetic wave (made of electric and magnetic fields) which doesn't need a medium. Sound is a mechanical wave that requires particles to vibrate and carry the energy.
500
Design a brief classroom experiment that lets students measure how frequency affects pitch.
Use a ruler held against a desk. By changing the length of the ruler hanging off the edge and "twanging" it, students can see that shorter lengths vibrate faster (higher frequency) and create a higher pitch.
500
Provide a short explanation of how information can be encoded into digital pulses and why that helps make transmission more reliable.
Information is converted into binary (0s and 1s) sent as "on" or "off" pulses. This makes it reliable because it’s easy for a computer to tell the difference between a pulse and silence, even if the signal is weak.