Answer:
trade and agriculture
Explanation:
i got it right on the test
Answer:
A galaxy with a disk and central bulge like a spiral galaxy, but with no spiral arms
Explanation:
A Lenticular galaxy is a kind of galaxy intermediate between elliptical galaxy and a spiral galaxy in the Morphological classification system of galaxies. They have a central bulge or disc just like a Spiral galaxy but lacks the arms of spiral galaxy. If looked edge on they appear to be spiral and if looked face on they appear to be elliptical.
The absence of spiral arms can be attributed to the absence of star formation. They mainly consists of ageing stars.
Answer:
3.73 * 10^16 photons/sec
Explanation:
power supply = 3.0 V
Emits 440 nm blue light
current in LED = 11 mA
efficiency of LED = 51%
<u>Calculate the number of photons per second the LED will emit </u>
first step : calculate the energy of the Photon
E = hc / λ
=( 6.62 * 10^-34 * 3 * 10^8 ) / 440 * 10^-9
= 0.0451 * 10^-17 J
Next :
Number of Photon =( power supply * efficiency * current ) / energy of photon
= ( 3 * 0.51 * 11 * 10^-3 ) / 0.0451 * 10^-17
= 3.73 * 10^16 photons/sec