Explore BrainMass

Explore BrainMass

    Phase Changes

    A phase change, or transition is the transformation of thermodynamic systems from one phase or state of matter to another. A phase in a thermodynamic system and the state of matter has uniform physical properties. During a phase transition, certain properties of the medium change discontinuously. This results in come external condition such as temperature and pressure. Phase transitions are commonly observed in nature. The most commonly used transition is between solid, liquid and gaseous states of matter.

    Phase transitions are classified based on the behavior of the thermodynamic free energy as a function of other thermodynamic variables.  First-order phase transition exhibits a discontinuity in the first derivative of the free energy with respect to some thermodynamic variable. Second-order phase transitions are continuous in the first derivative but exhibit discontinuity in the second derivative of free energy. This method is called the Ehrenfest’s classification. Although this classification method is useful, it is found to be inaccurate because it does not take into consideration where the derivative of free energy diverges. 

    © BrainMass Inc. brainmass.com May 25, 2024, 4:17 am ad1c9bdddf

    BrainMass Solutions Available for Instant Download

    Thin film interference and air gap of variable thickness

    ** Please see the attached file for the complete problem description ** Say you saw the following interference pattern due to air between two glass slides: (please see the attached file) a) What can you say about the thickness of the air gap across the slide? Is it uniform? What does it mean if there isn't any color (e.g.,

    Frequency is detected by the French submarine in the signal

    61. A French submarine and a U.S. submarine move toward each other during maneuvers in motionless water in the North Atlantic. The French submarine moves at speed vF = 50.00 km/h, and the U.S. submarine at vUS = 67.00 km/h. The French submarine sends out a sonar signal (sound wave in water) at 1.000 x 103 Hz. Sonar waves travel

    minimum distance from the mountain to the receiver

    Waves from a radio station have a wavelength of 262 m. They travel by two paths to a home receiver 14.1 km from the transmitter. One path is a direct path, and the other is by reflection from a mountain directly behind the home receiver. What is the minimum distance from the mountain to the receiver that produces destructive int

    Lowest frequency that produces interference

    Part 1 A microphone is located on the line connecting two speakers that are 0.524 m apart and oscillating 180° out of phase. The microphone is 1.97 m from the midpoint of the two speakers. What is the lowest frequency that produces an interference maximum at the microphone's location? Part 2 What is the next lowest fr

    Physics: Change of State

    *I only need solutions for these questions* 1. How much heat must be absorbed by 25g of ice at 0°C to change it to water without a change in temperature? Answer = 2.0kcal 2. A glass weighing 25g contains 75g of water at 27°C. how much ice will be needed to bring the temperature to 5°C? Answer = 20.71g

    Wave Motion: Amplitude and Wavelength

    Please answer the following: 1. How does wave amplitude change as waves propagate outward? 2. How does the resultant wave's wavelength change if we introduce two waves? Do you encounter similar effects in daily life?

    Interference for Sunlight Incidents

    7. Sunlight incident on a screen containing two long narrow slits 0.2mm apart casts a pattern on a white sheet of paper 2m beyond. What is the distance (in mm) separating the violet (lambda = 400nm) in the first-order band from the red (lambda = 600nm) in the second order? 8. A soap film has an index of refraction of 1.334. H

    Light Diffraction

    Please see attached file for full problem description. Interference effects are produced at point P on a screen as a result of direct rays from a 781 nm source and reflected rays off the mirror, as shown below If the source is 56 m to the left of the screen, and 0.87 cm above the mirror, find the distance y to the first dar

    Intereference of Sound Waves Without Approximations

    A lecturer is demonstrating two-slit interference with sound waves. Two speakers are used, 1.9 m apart. The sound frequency is 1120 Hz and the speed of sound is 343 m/s. Students sit facing the speakers in a row of seats 5 m away. Along the row of students, what is the spacing between the locations on either side of the

    Optical Waves

    A ray of light travelling down an optical fibre. See attached file for full problem description.

    Average Kinetic Energy of Gas Molecules

    What is the average kinetic energy of gas molecules at a temperature of 347 K in units of 10-21 J to two decimal places? If the molecules in the above problem have a mole mass of 49 g, to the nearest m/s what is their rms velocity?

    Phase Changes in a Bubble

    a.) A 1-cm3 air bubble at a depth of 419 meters and at a temperature of 4 oC rises to the surface of the lake where the temperature is 12.3 oC, to the nearest tenth of a cm3, what is its new volume? b.) How many micromoles (to 1 decimal place) of air is in the bubble?

    Measurement of Physiology - Respiration Signal

    A strap, instrumented to measure stretch, is worn around the chest to detect respiration whilst a subject is at-rest. The resulting signal is contaminated by electrical noise from the mains at 50 Hz with a similar amplitude to the respiration signal. Sketch what the contaminated signal might look like. The signal is then sample

    Destructive interference

    A mixture of red light (vacuum = 661 nm) and green light (vacuum = 551 nm) shines perpendicularly on a soap film (n = 1.41) that has air on either side. What is the minimum nonzero thickness of the film, so that destructive interference causes it to look red in reflected light? answer in nanometers

    Interference of light: thickness of the layer

    A layer of transparent plastic (n = 1.59) on glass (n = 1.52) looks dark when viewed in reflected light whose wavelength is 570 nm in vacuum. Find the two smallest possible nonzero values for the thickness of the layer. answer in nanometers

    Light reflected from air wedge formed by glass plates.

    I am having a bit of trouble with a problem in a algebra based physics course. When blue light (wavelength 589nm)is reflected from an air wedge formed by two flat glass plates, the bright fringes are 0.6cm apart. 1) How thick is the air wedge 5.0cm from the line of contact of the plates? (the wedge is viewed at normal inc