Heat Capacity and Specific Heat Quiz

Heat Capacity and Specific Heat

• Heat capacity is the minimum heat needed to change a substance's 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, aiding thermoregulation.
• Metals have low specific heat and are good heat conductors.
• Specific heat is related to particle forces and freedom.
• Calorimeters measure heat capacity.

Energy, Temperature, and Heat

• Energy is the ability to do work.
• Temperature is the average kinetic energy of a substance.
• Heat is energy transfer due to a temperature difference.
• Phase changes (e.g., freezing, melting, boiling) occur when energy is added or removed, altering the phase of a substance.
• Water's boiling point (212°F) can be affected by impurities and altitude.
• Higher altitude lowers the boiling point of water.
• Impurities (like salt) raise the boiling point and lower the freezing point of water.

Energy for Living Organisms

• Living organisms need energy for survival and reproduction.
• Energy is the ability to do work.
• The sun's energy powers life on Earth.
• Plants use photosynthesis, an endergonic process, to create sugar and oxygen from carbon dioxide and water.
• Cells use cellular respiration, an exergonic process, to break down sugar and produce ATP (the usable energy form).
• ATP provides energy for cellular processes, like muscle contraction.

Vibrations and Waves

• A vibration is a repeated back-and-forth motion from equilibrium.
• Periodic motion is repeated at regular intervals.
• Vibrations are the source of waves.
• Waves carry energy from one point to another without moving matter.
• Waves have crests (highest point), troughs (lowest point), amplitude (maximum height), and wavelength (distance between similar points).
• Higher amplitude means higher energy.
• Wavelength is inversely related to frequency (higher frequency = shorter wavelength).

Wave Propagation

• Wave propagation is the movement of waves.
• Wave speed (v) = frequency (f) × wavelength (λ).
• Wave speed is affected by factors like tension, rigidity, density, and temperature.
• Mechanical waves need a medium (e.g., sound waves).
• Electromagnetic waves do not need a medium (e.g., light).
• Transverse waves vibrate perpendicular to propagation (e.g., light waves).
• Longitudinal waves vibrate parallel to propagation (e.g., sound waves).
• Sound waves travel faster in denser, more rigid materials and at higher temperatures.

General Wave Characteristics

• Waves are disturbances that propagate through a medium.
• Wave properties include wavelength, frequency, amplitude, period, crests, and troughs.
• Frequency is the number of cycles per second.
• Wavelength is the distance covered by one cycle.
• Frequency and wavelength are inversely related (longer wavelength, lower frequency).
• Wave speed equals wavelength multiplied by frequency.
• Wave period is the time taken for one wave cycle.
• Amplitude is the distance between the midline and crest/trough.

Types of Waves and their Differences

• Waves are categorized into transverse and longitudinal based on the direction of particle motion.
• In transverse waves, particle movement is perpendicular to wave direction.
• In longitudinal waves, particle motion is parallel to wave direction.
• Mechanical waves require a medium to travel (e.g., sound waves).
• Electromagnetic waves don't need a medium to travel.
• Longitudinal waves can travel through solids, liquids, and gases.
• Transverse waves primarily travel through solids.
• Earthquake waves, including P-waves (longitudinal) and S-waves (transverse), were used to infer Earth's core properties – the outer core being liquid.
• Rayleigh waves combine longitudinal and transverse motions.