Recent content by Aoiumi

Homework Statement In order to achieve population inversion between two states that are separated by an energy difference of 3.5 eV, what wavelength of pumping should be used. Homework Equations Not sure. The Attempt at a Solution I have no idea where to start with this one...

Thank you!

Homework Statement The temperature of a blackbody is 500 C. If the intensity of the emitted radiation, 2.0 W/m^2, were due entirely to the most intense frequency component, how many quanta of radiation would be emiteed per second per square meter? Homework Equations λmaxT = 2.90 x...

That helped. Thank you!

Thank you for your help! So, Af = .0712 m^2 Then percent decrease should be (.0712 - .070685)/.070685 or 72%. Does this make sense?

Homework Statement A circular steel plate of radius 15 cm is cooled from 350 C to 20 C. By what percentage does the plates area decorate ? Homework Equations A=∏r^2 Af = Ai (1+2∂ΔT) specific heat of steel = 12 x 10^-6 The Attempt at a Solution r = 15 cm = .15 m Ai = .070685 m^2...

Homework Statement Light of wavelength 550 nm in air is normally incident on a glass plate (n=1.5) whose thickness is 1.1 X 10^-5 m. (a) What is the thickness of the glass expressed in terms of the wavelength of light in glass?(b) How many reflected waves will experience the 180 degree phase...

Okay. Thank you for the confirmation!

Homework Statement When two parallel slits are illuminated with monochromatic light of wavelength 632.8 nm, the angle between the center of the central maximum and the center of the second side maximum is .45 degrees. What is the distance between the parallel slits. Homework Equations...

Thank you so much for your clear explanation!

Homework Statement An object is placed 50 cm in front of a convex mirror and its image is found to be 20 cm behind the mirror. What is the focal length of the mirror? Homework Equations 1/d0 + 1/di = 1/f The Attempt at a Solution 1/50 + 1/20 = 1/-f 70/1000 = 1/-f f = 14.28...

Thank you for your explanation!

Homework Statement A flint glass plate 3.5 cm thick is placed over a newspaper. How far beneath the top surface of the plate would the print appear to be if you were looking almost vertically downward through the plate? Homework Equations N=1.66 for flint glass Apparent = d/n The...

Homework Statement An alarm clock makes a sound that has intensity 60 dB at a distance of 1 m. What is the sound intensity of 100 such clocks which are all 100m away? (A) 0.6 dB (B) 40 dB (C) 50 dB (D) 60 dB Homework Equations I1/I2 = R2^2/R1^2 The Attempt at a Solution If...

The ratio of the surface area of the two spheres would be 4pi/4pi(10)^2 or 1/100 I'm not sure how to set up the quation for power in dB based on the ratio of intensities I0/I = (p1/a1)/(p2/a2)?