Physics Rotational Mechanics Level: High School
A student sits on a rotating stool holding two 4 kg objects . When his arms are extended horizontally , the objects are 1.1 m from the axis of rotation , and he rotates with angular speed of 0.65 rad/sec . The moment of inertia of the student plus the stool is 4kg m^2 and is assumed to be constant . The student then pulls the objects horizontally to a radius 0.38 m from the rotation axis .Calculate the final angular speed of the student . Answer in units of rad/s .
Physics Properties Of Matter Level: High School
Explain the difference in molecular behavior for molecules in a solid compared each of molecules in a liquid and molecules in a gas . Assume that all three are the same temperature .
Physics Ray Optics Level: High School
Wave Optics
Assuming that I is the wavelength of light in oil , for an oil film on water , constructive interference occurs with the minimum film thickness of :I/4
I/2
I
2I
Physics Ray Optics Level: High School
Ray Optics
Gaussian pulses at a wavelength of 1310 nm traveling through a dispersive media of length L = 5km are each broadened by 5 nanoseconds . What is the maximum data rate than can be transmitted through this material for such pulses ? (state any assumptions)
Physics Ray Optics Level: High School
Ray Optics
The near-field distribution at the facet of an InGaAsP semiconductor laser is modeled as a Gaussian distribution with wo = 3 micro m perpendicular to the junction and wo = 6 micro m parallel to the junction . The free space wavelength of the semiconductor laser is 1400 nm . Estimate the far-field beam divergence(i) perpendicular
(ii) parallel to the junction of the laser
Physics Ray Optics Level: High School
Ray Optics
A fiber has an optical loss of 0.2 dB/km . What is the optical loss of a 50 km length of this fiber in units of dBs? If 1 mW of optical power at a wavelength of 1 = 1550 nm is coupled into this fiber , what will the output power be after 100 km ?
Physics Ray Optics Level: High School
Ray Optics
Consider a symmetric slab waveguide (or a circular step-index fiber waveguide) . If all parameters are held constant except the index of refraction difference between the core and the cladding increase , will the fraction of the energy (of the fundamental propagating mode ) in the cladding regions increase , decrease , or remain the same ? Explain in detail ?Physics Ray Optics Level: High School
Ray Optics
Information is encoded on an electromagnetic wave by modulating the amplitude . As the wave propagates through a dispersive medium , is the velocity of the information given by the group velocity . Phase velocity or the speed of light ? Does it matter if the information is digital or analogue ?Physics Ray Optics Level: High School
Ray Optics
A pulse of light has a gaussian shape in time with a band width of 3 GHz centered at a wavelength of 1 = 1.55 micro m . Does this pulse travel through a block of glass with a velocity determined by :(a) the group velocity
(b) the phase velocity
(c) the speed light of vacuum ?
Explain how ?Physics Ray Optics Level: High School
Ray Optics
When the light from an infrared laser (wavelength = 1560 nm ) travels from one medium with an index of refraction of n1 = 1.45 (glass) into a second medium with an index of refraction of n2 = 1.32 (water) .(i) only the frequency changes
(ii) only the wavelength changes
(iii)both the frequency and the wavelength change , and / or .
(iv)the frequency and the wavelength both remain the same . Explain
Physics Ray Optics Level: High School
Ray Optics
A few years ago , Cadillac announced the use red LEDs (wavelength 680 nm) instead of conventional bulbs with filaments for brake lights . The manufacturer claimed that because of their faster turn-on time , the stopping distance of a car following this new Cadillac could be reduced by up to 17 feet at 60 miles/hour . If this is so , what is the difference in the turn on time between the LED and the incandescent bulb that it replaces ?
Physics Ray Optics Level: High School
Ray Optics
How far does a plane wave with a free space wavelength of 980 nm travel in one nanosecond in a material with an index of refraction of 1.5 ?
Physics Ray Optics Level: High School
Ray Optics
The left face of a biconvex lens has a radius of curvature of 12.0 cm . and the right face has a radius of curvature of 18.0 cm . The index of refraction of the glass is 1.44(a) Calculate the focal length of the lens
(b) Calculate the focal length if the radii of curvature of the two faces are interchanged .
Physics Ray Optics Level: High School
Ray Optics
A submarine is 300 m horizontally out from the shore and 100m beneath the surface of the water . A laser beam is sent from the sub so that it strikes the surface of the water at a point 210 m from the shore . If the beam just strikes the top of a building standing directly at the water’s edge , find the height of the building .
Physics Ray Optics Level: High School
Wave Optics
In a Young’s double-slit experiment , a set of parallel slits with a separation of 0.100 mm is illuminated by light having a wavelength of 589 nm and the interference pattern observed on a screen 4.00 m from the slits .(a) What is the difference in path lengths from each of the slits to the screen location of a third-order bright fringe ?
(b) What is the difference in path lengths from the two slits to the screen location of the third dark fringe away from the center of the pattern ?
