Scientific Investigations & Variables
What is the independent variable in an experiment?
The factor that is changed on purpose by the experimenter.
What is empirical evidence?
Observations and measurements collected through investigation
State the law of conservation of energy.
In what direction does heat flow?
Warmer to cooler object.
What is white light made of?
A spectrum of colors (ROYGBIV).
What is the dependent variable in an experiment?
The factor that is measured or observed as a result of changes.
Give one benefit and one limitation of scientific models
Benefit: Simplifies complex systems; Limitation: Cannot show all details accurately
Define potential energy and kinetic energy.
Energy stored due to position. Energy of Motion
Convection: Heat transfer by...
Moving fluids
Do light and sound travel at the same speed?
No, light is much faster than sound
Why do scientists use controlled variables?
To keep conditions the same so only the test variable affects the outcome.
What is the difference between a scientific theory and a scientific law?
Theory explains why; law describes what happens consistently
Give one example of thermal energy, sound energy, and radiant energy.
Thermal: boiling water; Sound: music; Radiant: sunlight
Conduction: Heat transfer by...
direct contact
Name three ways light interacts with matter.
Reflection, refraction, absorption.
Name two ways scientists can organize data.
Tables, charts, graphs
Give an example of a scientific law
Law of Gravity, Newton's Laws
Thermal Equilibrium
Radiation: Heat transfer by...
Electromagnetic Waves
Name one material where sound travels faster and one where it travels slower.
Faster: steel; Slower: air.
Explain why repetition and replication are important in experiments
They confirm reliability and validity of results
Why do scientists debate and confirm results before accepting new ideas?
To ensure accuracy and avoid errors
Define temperature
The average kinetic energy of the particles in a substance.
Give two of the three state of matter phase changes that can occur when heat is added.
melting - solid -> liquid. evaporation - liquid -> gas, sublimation - solid -> gas
Give the types of Electromagnetic Radiation
A) Longest Wavelength
B) Highest frequency
C) Used in thermal cameras
A) Radio B) Gamma Rays C) Infrared