A typical blue supergiant star (the type that explode and leave behind black hol
ID: 1465522 • Letter: A
Question
A typical blue supergiant star (the type that explode and leave behind black holes) has a surface temperature of 2.1×104 K and radiates with a power 100000 times that of our sun. Our sun radiates at the rate of (3.86 *10^{26} W).
a)Assuming that this star behaves like an ideal blackbody, what is the principal wavelength it radiates?
b)Is the light visible?
c)If the power radiated by the star is 100000 times that of our sun, what is the radius of this star?
d)Compare its size to that of our sun, which has a radius of 6.96×105km.
Explanation / Answer
part A :
use Weins Displacemnt law as L T = constant = 0.0029
so
L = 0.0029/2.1 e 4
L = 138.1 nm
-------------------------------
no, it is not visibe ight
------------------------------------------
Intensity = power/area or P/r^2 is consatnt
so
P2/P1 = r2^2/r1^2
r2^2 = 6.96 e 8 * 6.96 e 8 * 100000
r2 = 2.2 e 8 km
-----------------------------------------------------
ration of r2 and r1 2.2 e 8/6.95 e 5 = 316.54
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.