Large quantities of dust should have been left behind after the creation of the

Question

Large quantities of dust should have been left behind after the creation of the solar system. Larger dust particles, comparable in size to soot and sand grains, are common. They create shooting stars when they collide with the earth's atmosphere. But very small dust particles are conspicuously absent. Astronomers believe that the very small dust particles have been blown out of the solar system by the sun.

Part A
By comparing the forces on dust particles, determine the diameter of the smallest dust particles that can remain in the solar system over long periods of time. Assume that the dust particles are spherical, black, and have a density of 2000 kg /m^{3} . The sun emits electromagnetic radiation with power 3.9 * 10^{26} W
D =.... m

Explanation / Answer

for a particle of radius r

m= 4/3r3*2000 = 8000r3/3

for a black body force due to the photons = Intensity/c

At a distance R from sun

force on the particle = P*r2/4R2c

gravitational force = GMm/R2 = GM*8000r3/3R2

Pr2/4R2c=GM*8000r3/3R2

3P/4GM*8000c=r

G=6.67E-11

M=2E30

c=3E8

r=2.9E-7

any particle with lesser radius will go out of solar system

Related Questions

Navigate

• Browse (All)
• Browse L
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.