The kinetic theory of gases presumes that intermolecular collisions are________________?
Show answer Hide answer
Answer: A. perfectly elastic
Explanation
One of the foundational postulates of kinetic theory is that molecular collisions are perfectly elastic. Kinetic energy is conserved during these molecular impacts with each other and container walls. No net energy is lost as heat during these microscopic mechanical collisions. Kinetic theory explains macroscopic gas properties through microscopic particle movements. Elastic collisions ensure that molecular speeds remain statistically constant in thermal equilibrium. Assumptions include negligible particle volume and absence of intermolecular forces in ideal gases.
Thermodynamic pressure derivation relies on momentum changes during these elastic collisions. Physicists use kinetic theory models to calculate root-mean-square speeds of gas molecules. Understanding particle collisions helps explain thermal conductivity and diffusion in gases. Option B describes inelastic collisions where kinetic energy would rapidly degrade into heat. Option C incorrectly assumes partial energy loss during molecular impacts. Option D mixes elastic and inelastic properties, contradicting basic kinetic theory postulates.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Enthalpy change of a system represents the heat added at___________________?
Show answer Hide answer
Answer: A. constant pressure
Enthalpy is defined mathematically as internal energy plus the product of pressure and volume. Differentiating this definition for a constant pressure process shows that enthalpy change equals added heat. This direct equ...
Q2. No substance can exist in the liquid state at____________________?
Show answer Hide answer
Answer: C. zero pressure
Liquid phase stability requires minimum molecular cohesion and confining pressure. At zero pressure, molecules lack the necessary surrounding pressure to remain condensed. Substances transition directly from solid to gas...
Q3. Kelvin-Planck’s law governs___________________?
Show answer Hide answer
Answer: C. conversion of heat into work
The Kelvin-Planck statement restricts heat engines from converting all absorbed heat into work. It dictates that some thermal energy must be rejected to a low-temperature sink. This principle governs the limitations of c...
Q4. Stirling and Ericsson cycles are categorized as__________________?
Show answer Hide answer
Answer: A. reversible cycles
Stirling and Ericsson cycles are composed entirely of isothermal and constant volume or pressure processes. Every individual process in these ideal cycles is internally reversible without internal friction or heat loss....
Q5. The Otto cycle consists of the following four processes____________________?
Show answer Hide answer
Answer: B. two isentropics and two constant volumes
The ideal Otto cycle models spark ignition internal combustion engine operations. Compression and expansion strokes occur adiabatically without heat exchange. Heat addition and rejection happen instantaneously at constan...
Q6. One watt is equal in value to__________________?
Show answer Hide answer
Answer: A. 1 Nm/s
One watt is defined scientifically as one joule of energy expended per second of time. Since a joule is equivalent to a newton-meter, a watt equals one newton-meter per second. Dimensional analysis confirms this fundamen...