Wednesday
November 26, 2014

Search: light

Number of results: 4,755

Physics - light
1. Blue light and yellow light combine to produce white light because they constructively interfere. Explain why 2. You shine yellow light on an object and it appears black. What color might the object be if illuminated by red light? Justify your response.
May 1, 2011 by Quinten

Physics
Subject: Light and Geometric Optics Question: Where must a light source be placed in front of a concave mirror for a) light energy to be concentrated to a single point b)the light to be reflected in a parallel beam?
May 22, 2010 by Emily

chemistry-light
the SI Unit of length is meter,which is defined as the lenght equal to 1,650,763.73 wavelengths of light of the light emitted by a particuar energy transition in krypton atoms.calculate the frequency of the light to three significan figures.
November 3, 2011 by nja

physical
Light is shone on a metal and photoelectrons are emitted. Can you tell me the three things from the list below which might cause the photoelectron emission to stop. Decreasing the intensity of the light Increasing the frequency of the light Decreasing the wavelength of the ...
December 10, 2008 by trigger

science
Electromagnetic radiation with a wavelength of 700 nm would be: a)x-rays b)red light c)violet light d)ultraviolet light e)microwaves I thought it would be visible light but that's not an option.
September 12, 2010 by Liah

physic
Light is shone on a metal and photoelectrons are emitted. Can you tell me the three things from the list below which might cause the photoelectron emission to stop. Decreasing the intensity of the light Increasing the frequency of the light Decreasing the wavelength of the ...
December 13, 2012 by vanya

science
Light is shone on a metal and photoelectrons are emitted. Can you tell me the three things from the listbelow which might cause the photoelectron emission to stop. Decreasing the intensity of the light Increasing the frequency of the light Decreasing the wavelength of the ...
December 14, 2012 by centya

physics
Light is shone on a metal and photoelectrons are emitted. Can you tell me the three things from the listbelow which might cause the photoelectron emission to stop. Decreasing the intensity of the light Increasing the frequency of the light Decreasing the wavelength of the ...
December 17, 2012 by centya

physiiics
Which of the following is correct for the two coherent light waves to produce zero light? The light waves should travel in perpendicular directions. The light waves are in phase with each other The light waves are out of phase with each other. The light waves should pass ...
February 11, 2013 by ooommgggg

physics
A diamond's index of refraction for red light, 656 nm, is 2.410, while that for blue light, 434 nm, is 2.450. Suppose white light is incident on the diamond at 32.2. Find the angles of refraction for red and blue light. red light? blue light?
May 14, 2013 by A

Physics
When you approach a blinking source of light, the frequency of its blinking is seen to: decrease, increase, or remain the same always. I THINK IT IS INCREASING. If you are traveling at close to the speed of light and shine a flashlight out in front of you, a third observer at ...
May 3, 2008 by clark

Physics
A balloon appears to be yellow when seen in white light. Explain the colour it will appear in a) green light and b) magenta light. I really don't undestand the subtractive theory of light, and it applies to this question. Can you plese explain to me how to get the answer? Thanks
April 25, 2010 by Emily

science
Which statement explains why light from sun can warm up water in a glass? a)light travels very fast. b)light travels in straight lines. c)water reflects light energy. d)water absorbs light energy.
December 2, 2013 by Anonymous

Physics
Why is it necessary to collimate the light source before using the prism to disperse the light? A. If white light enters the prism with different angles, some of the blue light will exit the prism with the same angle as the orange light. B. If white light enters the prism with...
October 22, 2012 by Kyle

Physical Science
These are two questions that I need help with: 1.What statement about light traveling through water and glass is true? A.Water and glass absorb different colors of light B.Light changes colors as it passes from water to glass C.Light travels at different speeds in water and ...
May 9, 2009 by mysterychicken

Science
A plant deprives of light dies. Which of the following best explains why this happens? 1-The plant needs light to make it's food 2-Light allows the plant to make food for other organisms 3-Without light, the plant has no signals to be able to grow* 4-Plants need light to ...
February 13, 2014 by Anonymous

Physics
Which of the following is correct for the two coherent light waves to produce zero light? The light waves should travel in perpendicular directions. The light waves are in phase with each other. The light waves are out of phase with each other. The light waves should pass ...
October 19, 2012 by Blah

Microscopes
How do light microscopes work? a. Light microscopes use an electron beam to create an image of a specimen. b. Light microscopes use a combination of light and lenses to magnify a specimen. c. Light microscopes use a tiny tip that traces a specimen, enlarging it. d. Light ...
September 17, 2013 by Anonymous

physics
Maxwell's equations proved that a. Light is a mechanical phenomena b. Light is a chemical phenomena c. Light is a phenomenal phenomena d. Light is an electromagnetic phenomena I think the answer is either a or d. But I'm pretty sure its d Thank you for any help and happy ...
December 16, 2012 by Katie

physics
A light year (speed of light 2.998x10^8 m/s) is the distance light travels in a year. How many meters are there in 1 light year? (Answer:9.45x10^15 m/yr)
September 10, 2010 by Anonymous

Physics
A certain type of laser emits light that has a frequency of 4.7 1014 Hz. The light, however, occurs as a series of short pulses, each lasting for a time of 2.8 10-11 s. (a) How many wavelengths are there in one pulse? (b) The light enters a pool of water. The frequency of the ...
April 25, 2013 by Anonymous

speed of light
Can the speed of light be legislated? Explain your reasoning. As best as we know, the speed of light is a fundamental constant of the universe. I have no idea of the meaning "legislated". Someday they may pass laws and light will have to slow down. After the laws are passed ...
August 21, 2006 by Anonymous

Science
A green leaf is reflecting a. no light b. red light c. green light d. all light C
January 20, 2014 by Hayden

Physical Science
In which of these cases does a ripe banana apear black, red light/green light or blue light? Why?
April 18, 2008 by Rachel

chemistry
The human eye responds to a light stimulus (generates a sensation of "light") upon receiving light energy of 10eV (and more). If we take 6000 angstroms as the average wavelength, how many photons must the eye receive to register a light sensation?
December 19, 2013 by Peter

Chem help?!
Which color light is diffracted at a greater angle, red light or yellow light?
November 14, 2007 by Chuck

physics
An object emitting 500nm wavelength light moves away from you at half of the speed of light. What is the observed wavelengths of the light?
February 12, 2014 by Barbara Davis

physics ( help FAST)
if you were to move the light sencor in an experiment 5 times further from the light as it was before, by what fraction would the light intensity change????
May 19, 2011 by D.J

Science Help
How does a periscope work when it has 2 mirrors and light? A.Lenses refract the light B.Light bends as it travels and mirrors bend the light more C.Light travels in a straight line and the mirrors reflect the light D.Lenses and mirrors reflect the light Reflect means to bounce...
March 21, 2012 by Derrick

Science
How does a periscope work when it has 2 mirrors and light? A.Lenses refract the light B.Light bends as it travels and mirrors bend the light more C.Light travels in a straight line and the mirrors reflect the light D.Lenses and mirrors reflect the light Reflect means to ...
March 21, 2012 by Derrick

calculus
a revolving light is located at 5 km from a straight shoreline with a constant angular velocity. what velocity does the light revolve if the light moves along the shoreline at the rate of 15km/min when the beam of light makes a angle of 60 with the shoreline?
September 3, 2014 by dinesh

Chemistry
How does light energy work? Is red light the lowest? or is blue light?
June 14, 2012 by tfun

science- help needed.
each statement is false. rewrite each one as a true statement,showing as much scientific understand as possible. 1. light waves travel slower than sound waves. 2.a black object will reflect white light. 3.a translucent object lets no light through. 4.an orange object will ...
November 30, 2008 by ruby127

Science grade 3
Does light always flow from light to dark places? T or False and explain. I say no becasue light shines and it does not flow Photons are emmitted and radiate in all directions until they are absorbed or reflected. So no is correct. They do not flow from light to dark. Thank you
May 30, 2007 by Marie

physics
light is an electromagnetic wave and travels at a speed of 3.00 x 108 m/s. the human eye is most sensitive to yellow-green light which has a wavelength of 5.45 x 10-7 m. what is the frequency of this light?
November 18, 2012 by Joe

Physics
Does blue light or orange light have a larger index of refraction? Blue light is bent more by a prism than orange light. Does blue light or orange light have a larger index of refraction in glass? A. Blue B. Orange If you know the answer to this, could you also explain why? ...
October 29, 2009 by Jeff

Physics
Rank in order the following according to their speeds, from fastest (1) to slowest (5): (i) 425-nm-wavelength light through a pane of glass, (ii) 500-nm-wavelength light through air, (iii) 540-nm-wavelength light through water, (iv) 670-nm-wavelength light through a diamond, ...
February 2, 2013 by Cassie

physics
Question Part Points Submissions Used 1 2 3 4 0/0.37 0/0.37 /0.37 /0.37 4/15 1/15 0/15 0/15 Total 0/1.48 ...A diamond in air is illuminated with white light. On one particular facet, the angle of incidence is 46.05. Inside the diamond, red light ( = 660.00 nm in vacuum) ...
May 4, 2014 by ryan

physics
b. If you are cruising down the road at 50 mph and a policeman with a radar gun (wavelength 1 cm) reflects radar light off your bumper, what wavelength of radar light does he get back? Assume the policeman is stationary, and you are moving towards him. Light that gets ...
April 15, 2012 by DJ

Physics
I am to fill in the blanks without a word bank, my answers are in brackets. 1. When light waves reflect from media in which the speed of light is slower, their phase (crest or trough) is ____ 2. The trick to being able to observe interference patterns for light waves in to ...
July 26, 2014 by Liz

Physics
We hear people talk of "ultraviolet light" and "infrared light." Why are these terms misleading? Why are we less likely to hear people talk of "radio light" and "X-ray light"?
February 22, 2008 by Shirley

Chemistry
Purple light in the visible region of the electromagnetic spectrum has a shorter wavelength than does the green region of the spectrum. Which of the following can you conclude? Is it: a)a photon of purple light has a higher frequency than does a photon of green light or b) ...
November 17, 2011 by Lisa

Physical Science
I need help with some of these questions: 1.If you look at a red leaf, what describes what happens when you see it? A.The leaf absorbs red light from our eyes B.Our eyes reflect red light back to the leaf C.Red light reflected from the leaf enters our eyes D.The leaf radiates ...
May 9, 2009 by mysterychicken

Physics-Light
light diffraction help? a single monochromatic indigo light source is shined through an etched, flat prism with a slit separation of .0250mm. the resulting interference pattern is viewed on a screen 1.25 m away. the third Maximum is found to be 6.6 cm from the central maximum...
October 27, 2014 by Eiban

Physics
When light travels from air to glass, which one of the following is not dependent on the index of refraction of the glass? A- The speed at which lught travels in the glass B- The angle through which light is deflected on entering the glass C- The frequency of the light in the ...
June 12, 2006 by David

physics
1.The greenish blue of water is evidence for the A) interaction between green and blue frequencies of light. B) reflection of red light. C) reflection of greenish-blue light. D) absorption of greenish-blue light. E) absorption of red light. 2.Atmospheric refraction tends to ...
May 22, 2008 by Sandhya

calculus
A light house is 1 km off shore. A marathoner is running along the shore. The search light on the light house is rotating at a rate of 1/6 revolution per minute when the runner is 3 km from the point on the shore that is the closest to the light house.The runner is illuminated...
March 25, 2008 by samir

Physics
Two stars are 8 light years from earth (a light year is the distance light travels in one year). The 550 nm light from the two stars can be barely distinguished in the diffraction pattern of 90 cm wide single slit. How far apart are the stars?
May 2, 2012 by jackmo

Math
A consumer buys n light bulbs, each of which has a lifetime that has a mean of 800 hours, a standard deviation of 100 hours, and a normal distribution. A light bulb is replaced by another as soon as it burns out. Assuming independence of the lifetimes, find the smallest n so ...
April 27, 2011 by Alex

Math
A consumer buys n light bulbs, each of which has a lifetime that has a mean of 800 hours, a standard deviation of 100 hours, and a normal distribution. A light bulb is replaced by another as soon as it burns out. Assuming independence of the lifetimes, find the smallest n so ...
April 27, 2011 by Lo

Math
Daphne replaced light bulbs in her mothers store.She had 3/4 of a box of light bulbs. She used 1/3 of the bulbs. a. What fraction of the box of light bulbs was left? b. How many light bulbs are in a full box? Explain. Thanks to everyone who helps answer questions it is ...
October 25, 2012 by Cherie

physics/light reflection
A light of ray is incident at an angle of 58degrees on the plane surface of a block of glass of refractive index 1.60. Some light is reflected on the other side of the normal at the same angle as the angle of incidence. Find: a.the angle between the light reflected from the ...
October 24, 2012 by Help please

Chemistry
The distance to our nearest neighboring Star, is 4.4 light years. If there are 9.460x10^12 km in 1 light year, how far is this in miles? So this is how I solved: 9.460x10^12 km x 1mi/1.61km x5.878x10^12 miles/1 light year x4.4 light years My answer is 1.51x10^26 which i know ...
September 28, 2011 by Anonymous

Phy
The index of refraction for a diamond for red light of wavelength 655 nm is 2.35, while that for blue light of wavelength 437 nm is 2.26. Suppose white light is incident on the diamond at 29.5. Find the angle of refraction for red light. Answer in units of 
February 18, 2012 by Joila

Physics
Which of the following is an example of diffuse reflection? light reflected from the surface of a dry asphalt roadway light reflected from the surface of a calm lake light reflected from the surface of glossy paper light reflected from the surface of a shiny metal plate
October 25, 2012 by Anonymous

Physics
Which of the following is an example of diffuse reflection? light reflected from the surface of a dry asphalt roadway light reflected from the surface of a calm lake light reflected from the surface of glossy paper light reflected from the surface of a shiny metal plate
October 29, 2012 by Confused

Biology
O2 is a product of: A. light-dependent reactions. B. light-independent reactions. C. light-capturing events. D. All of the choices are correct. Is the answer D?
January 20, 2014 by Anonymous

biology help
Is photosynthesis only occurring during the daytime? What happens when there is no light? What is the relationship between light dependent and light independent reactions in photosynthesis?
July 10, 2011 by miyagi

analogies
furnace:fireplace::lamp: ? log,street light,light bulb, headlight,candle is light bulb correct?
April 11, 2011 by sally

Physics
Which of the following is an example of diffuse reflection? light reflected from the surface of a dry asphalt roadway light reflected from the surface of a calm lake light reflected from the surface of glossy paper light reflected from the surface of a shiny metal plate No one...
October 26, 2012 by Anonymous

physical science
describe your motio when you are on a swing in terms of kinetic and potetial energy. at which point during your motion is each type of energy the greatest Potential energy is hghest when the elevation is highest. Potential energy is lowest (and kinetic energy highest) when the...
January 9, 2007 by allie

MATH
A light year is the distance that a light travels through a vacuum (space without matter) in one year. A light year is about 9.46 x 10^12km. The distance to the spiral galaxy NGC 4603 is about 1.08 x 10^8 light years. What is the distance in km?
March 31, 2011 by Maria

Geometry
A 195 cm person casts a 2.1 m shadow in the light of a street lamp. If the person is standing 4.2 m from the light, how tall is the light?
September 12, 2010 by Cindy

Electricity
The best answer is c, but a is also true if the wavelength of the light is chosen correctly. The intensity of the light does not determine the emission of the electrons, the wavelength (energy of light photons) is what determines. c
August 20, 2005 by bobpursley

math
mr foster places 11 garden light along 80- meter path.each light an eqal distance apart .haw far away is the sixth garden light from the second?
February 4, 2012 by omraan

physics
Suppose the time taken for light to bounce to and fro between the parallel mirrors of a light clock is 1 second, in the frame of reference of the light clock. As seen by another observer moving at high speed at right angles to the to-and-fro motion of the bouncing light, the ...
December 8, 2011 by lisa

physics
You are in the lab with a 10 V battery. You have a 10 W light bulb and you want to put 1/2 A of current through the light bulb and 5 V across the light bulb. This will allow the light bulb to have a brightness proportional to 2.5 W. Assuming any resistors that you need, design...
February 26, 2013 by jamie

psychology
* Take about 15 index cards and a flashlight that is opaque on all sides (so that light shines only through the front) into a very dark room. * Place all 15 cards over the beam of light. * Slowly remove the cards one at a time until you can barely detect the light, and then ...
March 30, 2010 by ingrid

college physics
You are in the lab with a 10 V battery. You have a 10 W light bulb and you want to put 0.75 A of current through the light bulb and 7.5 V across the light bulb. This will allow the light bulb to have a brightness proportional to 5.625 W. Assuming any resistors that you need, ...
February 26, 2013 by michelle

physics
Laser light is commonly used to demonstrate double-slit interference. Explain why laser light is preferable to light from other sources for observing interference. Doesn't double slit interference work best on monochromatic light? yea
April 27, 2007 by anonymous

phys
A motorist is driving at 20m/s{\rm m/s} when she sees that a traffic light 200m{\rm m} ahead has just turned red. She knows that this light stays red for 15s{\rm s} , and she wants to reach the light just as it turns green again. It takes her 1.0s{\rm s} to step on the brakes ...
September 16, 2014 by Av

physics
In astronomy, distances are often expressed in light-years. One light-year is the distance traveled by light in one year. The distance to Alpha Centauri, the closest star other than our own sun that can be seen by the naked eye, is 4.7 light-years. Express this distance in ...
March 3, 2008 by rick

Physics
A 75 W light source consumes 75 W of electric power. Typically only about 5% of this energy is emitted as visible light of wavelength 600 nm. (a) Calculate the frequency of the emitted visible light. (b) How many photons per second of visible light does the source emit? (c) Is...
April 28, 2008 by J

Trig
a sailor out in a lake sees two likght houses 11km apart along the shore and gets bearings of 285degrees from his present position for light house A and 237degrees for light house B. From light house B, light house A has a bearing of 45degrees. How far to the nearest kilometre...
July 21, 2010 by Sonia

physics
A 75 W light source consumes 75 W of electric power. Typically only about 5% of this energy is emitted as visible light of wavelength 600 nm. (a) Calculate the frequency of the emitted visible light. (b) How many photons per second of visible light does the source emit? (c) ...
October 21, 2011 by A 75- light source consumes 75 of electrical power. Assume all this energy goes into emitted light

science
light trsavels at 3*10 m/s. an astrounaut shines a flash light in space. 4 hours later a martian sees a light from the astrounaut. how far away is mars from the astrounaut?
April 17, 2013 by allison

math
A street light (light source) is 15 m above the ground. A ball is freely released from a location of 9 m from the light with the same elevation as the lights. While the ball is falling, it casts a shadow on the ground. Assuming the gravity is 10 m/s2, calculate the speed of ...
August 8, 2012 by rolan

Physics
We can reasonably model a 75 W incandescent light bulb as a sphere 6.0 cm in diameter. Typically, only about 5% of the energy goes to visible light; the rest goes largely to non-visible light infrared radiation. (a) What is the visible light intensity (in W/m^2) at the surface...
August 11, 2010 by Brittany

Physics - General Physics
Violet light and red light travel through air and strike a block of plastic at the same angle of incidence. The angle of refraction is 30.700 for the violet light and 31.380 for the red light. The index of refraction for violet light in plastic is greater than that for red ...
September 1, 2014 by Kace

a
Consider what you have learned so far about the use of light in medieval, African, and North American buildings and artworks. Select a specific example, fully identified, and address the following in your discussion posting: How was light and height used in the art and ...
May 2, 2012 by janvert

Astronomy
Few question about astronomy: 1.how many centimetres is equivalent to a light-nanosecond 2. How long is an astronomical unit (AU) in light-minutes (1min, i.e., the distance that light travels in a vacuum in one minute)? Please show the calculation if there is any Thanks
September 13, 2011 by KD

brain teaser
You are standing outside a closed door. On the other side of the door is a room that has three light bulbs in it. The room is completely sealed off from the outside. It has no windows and nothing can get in or out except through the door. On the outside of the room there are ...
September 14, 2011 by Tony

physics
A light bulb is wired in series with a 133-Ω resistor, and they are connected across a 120-V source. The power delivered to the light bulb is 22.5 W. What are the two possible resistances of the light bulb?
January 25, 2011 by joe

algebra
A light-year is the distance that light travels in one year. Find the number of miles in a light-year if light travels 1.86 105 miles/second. (Round to one decimal place, and assume that there are 365 days in a year.)
March 12, 2010 by larry

physics
An observer uses a 10 sided mirror to measure the speed of light. A clear image occurs every one-tenth of a rotation when the mirror is rotating at 4.31x10^2 rev/s. The total path of the light pulse is 60 km, measured from the light source to the mirrors and reflected back to ...
September 20, 2013 by sam

Introduction to Electricity and Circuits
A light bulb is wired in series with a 142 resistor, and they are connected across a 120 V source. The power delivered to the light bulb is 22.3 W. What are the two possible resistances of the light bulb?
February 6, 2011 by Jiji

math
a light year is the distance light travels in one year. one light year is about 5.9x10^12 mi. If it takes light 3 months to travel from one star to another, about how far apart are the stars? 5.9x10^12/12*3 I got 1.5x10^12 mi Is this correct?
January 9, 2014 by Elle

Physics - Help!
An incident light is monochromatic and of wavelenght 600nm, the kinetic energy of the electron is 2.56 x 10^(-20)J. For light of wavelenght 400nm, it is 1.92 x 10^(-19)J. Use the above information to estimate the value of Planck's constant,h and the work function,W of the ...
April 26, 2007 by Sola

snell's law
An equilateral prism of silica flint glassis used to refract white light. The indexof refraction of silica flint is 1.66 forviolet light and 1.62 for red light. What is the angle of separation between the violet and red ends of the rainbow produced when the ray of white light ...
April 22, 2010 by PEACE :)

Physics ( light)
A student doing Young's experiment measures a distance of 6.0 cm between the first and seventh nodal points on a screen located 3.0 m from the slit plate. a) if the slit seperation is 220^ -6, what is the wave length of light being used ? b) what colour is the light ?
June 17, 2012 by David E.

algebra 1
On a restaurant sign, 14 light bulbs must be replaced. These light bulbs represent 3/8 of the total number of light bulbs on the sign. If b represents the total number of light bulbs, which equation could be used to determine the value of b?
March 17, 2014 by alibaba

Physics
Brain buster: A laser sends red light of wavelength 650 nm from air into water in a swimming pool. The index of refraction of the water is 1.33. (a) What wavelength will the light have in the water? (b) What colour would light of this wavelength appear if it were in air? (c) ...
December 8, 2012 by Hanu2012

Physics Plz help me
If a galaxy is traveling away from us at 2.0% of the speed of light, roughly how far away is it? t= light years I got 2.4x10^8 light years but its wrong please help me out...thank you
May 6, 2013 by Leila

architecture
Consider what you have learned so far about the use of light in medieval, African, and North American buildings and artworks. Select a specific example, fully identified, and address the following in your discussion posting: How was light and height used in the art and ...
May 2, 2012 by Rober

Science
In physics,Light chapter: A/c to huygens principle light travels in the form of Waves but When he explained Ripple's tank experiment he showed that light travels in the form of particles{in diagram}Why?
August 21, 2011 by Akhila

Physics
Red light (n = 1.520) and violet light (n = 1.538) traveling in air are incident on a slab of crown glass. Both colors enter the glass at the same angle of refraction. The red light has an angle of incidence of 20.97. What is the angle of incidence of the violet light? Give ...
April 10, 2013 by Tim

Physics
Red light (n = 1.520) and violet light (n = 1.538) traveling in air are incident on a slab of crown glass. Both colors enter the glass at the same angle of refraction. The red light has an angle of incidence of 26.50. What is the angle of incidence of the violet light?
March 6, 2012 by DCM

physics
Red light (n = 1.520) and violet light (n = 1.538) traveling in air are incident on a slab of crown glass. Both colors enter the glass at the same angle of refraction. The red light has an angle of incidence of 26.50. What is the angle of incidence of the violet light?
March 7, 2012 by DCM

Physics
3. Yellow light travels through a glass block at a speed of 1.97x108 m/s. The wavelength of the light in this type of glass is 3.81x10-7 m. What is the frequency of yellow light?
February 24, 2014 by Tara

physics
a very bright source of red light has much more energy than a dim source of blue light, but the red light has no effect in ejecting electrons from a certain photosensitive surface. why is this so?
April 18, 2011 by myles

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