School and Work

Home >All Categories > Science & Mathematics >Physics >Open Question cindy Member since:February 20, 2011Total points:7 (Level 1)Unpolarized light with an intensity of 275 W/m2 passes through two polarizers whose transmission axes are at an angle of 30.0? with respect to each other. What is the intensity of the light transmitted through both polarizers?Answer Question

Be the first to answer this question.

View the original article here

Home >All Categories > Science & Mathematics >Physics >Open Question Heartill... Member since:April 21, 2011Total points:65 (Level 1)A light bulb is wired in series with a 144-O resistor, and they are connected across a 120-V source. The power delivered to the light bulb is 23.0 W. What are the two possible resistances of the light bulb?
lower value O
higher value OAnswer Question

Be the first to answer this question.

View the original article here

Stuck on a problem in this physics assignment. Unsure whether or not I should use the ?t' = t / sqrt (1- v^2/c^2).

Problem~

An elementary particle called a pi meson (or pion for short) has an average lifetime of 2.6 10-8 s when at rest. Suppose that a pion moves with a speed of 0.9c relative to Earth.

(a) Find the average lifetime of the pion as measured by an observer on Earth.

s

(b) Find the average distance traveled by the pion as measured by the same observer.
m

(c) How far would the pion have traveled relative to Earth if relativistic time dilation did not occur?
m

View the original article here

Sorry, I could not read the content fromt this page.

View the original article here

Sorry, I could not read the content fromt this page.

View the original article here

Sorry, I could not read the content fromt this page.

View the original article here

Assume 3 significant figures.

visible light (490 nm) to kJ

Sorry, I could not read the content fromt this page.

View the original article here

Sorry, I could not read the content fromt this page.

View the original article here

Sorry, I could not read the content fromt this page.

View the original article here

The green pigments are chlorophyll In the chloroplasts.

1.Green light is reflected.
2.Electrons are energised and result in O2, ATP & NADPH production in the light stage of photosynthesis.

View the original article here

Sorry, I could not read the content fromt this page.

View the original article here

I often hear that larger mirrors are used in telescopes in order to collect more light, in order to create brighter images, but this doesn't fit with observations of non-telescopic mirrors. Objects don't look brighter in bigger mirrors than smaller ones, so why would bigger mirrors in telescopes create brighter images?

Also, why is it that refracting telescopes have fallen out of favor and instead most advanced telescopes today are reflecting, but for camera lenses refracting lenses are preferred to reflecting ones?

View the original article here

Home >All Categories > Science & Mathematics >Physics >Open Question King Member since:January 21, 2007Total points:80 (Level 1)At what distance from a 21 W electromag-
netic wave point source (like a light bulb) is
the amplitude of the electric field 33 V/m?
All quantities given here are in the SI units.
Answer in units of m.Answer Question

Be the first to answer this question.

View the original article here