# Physics

posted by .

Does one Candela (SI Unit for lumious intesnity) = lumens per metre squared,

i.e. 1 Cd = 1 lum/m^2

if not, what is the relationship between candela and lumens?

• Physics -

They don't measure the same thing. Lumens measures light output,and candela measures light on a surface.

• Physics -

Then, in the light intensity equation E=L/r^2, where E is illumination, L is luminous intensity and r is distance, what are the units of each factor?

• Physics -

Candela refers to lumens emitted per steradian in a particular direction by a pointlike source. It is related to the old unit "candle". It does not refer to the lumens hitting a surface per area, that is called illuminance, and is measured in lux.

In the equation E = L/r^2, E (illuminance) is in lux, L is in candelas and r is in meters.

http://en.wikipedia.org/wiki/Candela

## Similar Questions

1. ### Physics

Mere and Ruth investigated the relationship between the applied force, F, and the extension, x of a spring. The results they obtained are shown in the table below. Force F (N) Extension x (M) 0.0 0.0 2.0 0.033 4.0 0.066 6.0 0.099 8.0 …
2. ### physics

Mere and Ruth investigated the relationship between the applied force, F, and the extension, x of a spring. The results they obtained are shown in the table below. Force, F (N) Extension, x (m) 0.0 0.0 2.0 0.033 4.0 0.066 6.0 0.099 …
3. ### Algebra 2 Honors

The amount of light emitted from a battery indicator bulb pulses while the battery is charging. This can be modeled by the equation y = 60+60sin[(pi/4)t] , where y is the lumens emitted from the bulb and t is the number of seconds …

The average light output for a domestic bulb is 80 lumens with a range of 4 lumens when process is in control. Sample size is 6. What are the CL, UCL and LCL for the X-Bar and R charts?
5. ### Science

19. Which of the following base unit definitions was changed from being based on an arc of the earth to a time interval of light?
6. ### college algebra

Use a calculator to help solve the problem. The intensity I of light (in lumens) at a distance x meters below the surface is given by I = I0 k x, where I0 is the intensity at the surface and k depends on the clarity of …
7. ### algebra

Fiber-optic cables are used widely for internet wiring, data transmission, and surgeries. When light passes through a fiber-optic cable, its intensity decreases with the increase in the length of the cable. If 1500 lumens of light …
8. ### algebra 1

Fiber-optic cables are used widely to increase the speed and accuracy of data transmission. When light passes through a fiber-optic cable, its intensity decreases with the increase in the length of the cable. If 1700 lumens of light …
9. ### algebra worksheet help please

Fiber-optic cables are used widely for Internet wiring, data transmission, and surgeries. When light passes through a fiber-optic cable, its intensity decreases with the increase in the length of the cable. If 1,500 lumens of light …
10. ### Maths

If a unit is 465mm x 320mm how much will it cost for one unit if its priced at \$25 per metre squared

More Similar Questions