Heat and Energy Transfer Quiz

Heat and Energy Transfer

• Heat capacity is the minimum heat absorbed by a substance to change its temperature by one unit.
• Specific heat capacity is the heat capacity per gram of a substance.
• Molar heat capacity is the heat capacity per mole of a substance.
• Water has a high specific heat, essential for life's thermoregulation.
• Metals have low specific heat and are good heat conductors.
• Specific heat capacity relates to particle interactions (degrees of freedom, forces).
• Calorimeters measure heat capacity.
• Energy is the ability to do work.
• Temperature is the average kinetic energy of a substance.
• Heat is energy transfer due to temperature difference.
• Phase changes occur when sufficient energy is added to a substance resulting in changes in states of matter. Example include, water freezing into ice, ice melting into water, or water boiling into water vapor.

Phase Changes and Boiling Points

• Water boils at 212°F, though this can change.
• Altitude lowers water's boiling point.
• Impurities (like salt) raise water's boiling point and lower its freezing point.
• This is why salt is used in cooking pasta.
• At the boiling point, temperature remains constant while added heat changes the substance into another phase as potential energy increases.

Energy Transformations in Living Organisms

• Living organisms need energy for survival and reproduction.
• Photosynthesis (endergonic) is used by plants to make sugar and oxygen from carbon dioxide and water using energy from the sun
• Cellular respiration (exergonic) is used by cells to break down sugar into ATP, the cell's usable energy source.
• The products of cellular respiration (carbon dioxide and water) are used by plants in photosynthesis.

Vibrations and Waves

• Vibration is a repeated back-and-forth motion from an equilibrium position.
• Periodic motion is repeated motion at regular intervals.
• Waves are disturbances transferring energy, not matter.
• Waves have:
  • Crest: Highest point.
  • Trough: Lowest point.
  • Amplitude: Maximum height from equilibrium. Higher amplitude = more energy.
  • Wavelength: Distance between identical points (e.g. crest to crest).
  • Frequency: Number of waves passing a point per unit time. Higher frequency = shorter wavelength.

Wave Propagation and Types

• Wave propagation is the movement of waves.
• Wave speed (v) = frequency (f) x wavelength (λ).
• Factors affecting wave speed include tension, rigidity, density, and temperature.
• Mechanical waves require a medium (e.g. sound).
• Electromagnetic waves don't require a medium (e.g. light/electromagnetic waves).
• Transverse waves: Particle vibration perpendicular to wave propagation (e.g. waves on a string).
• Longitudinal waves: Particle vibration parallel to wave propagation (e.g. sound waves).
• Earth's core structure is determined by which earthquake waves (longitudinal vs. transverse) can travel through it

Wave Characteristics

• Waves are propagating oscillations in a medium.
• Key wave characteristics include wavelength, frequency, amplitude, period.
• Frequency is related to the number of wave cycles per second.
• Wavelength is the distance covered by one wave cycle.
• Wave speed is equal to the product of wavelength and frequency.
• Longer the wavelength the lower the frequency.
• Amplitude is the distance from the midline to the crest (or trough).
• Frequency is related to wave period; period is the time to complete one wave cycle.

Test your knowledge on heat capacity, specific heat, and the principles of energy transfer. This quiz covers essential concepts related to temperature, heat, calorimetry, and phase changes of substances. Perfect for students studying thermodynamics in science courses.