A) A typical dust grain has a radius of about 0.1 micrometers and a mass of  10-14   grams. Roughly how many dust particles are in a cloud containing 1000 Msun of dusty gas if 1% of the cloud's mass is in the form of dust grains?  B) What surface area would be covered by these grains if you put them side by side? Assume these grains are spherical. Answer in square light-years. C) Estimate the total surface area covered by the cloud assuming it's matter density is like that of a typical molecular cloud, about 10-21 g/cm3 (Hint: first calculate the clouds volume from it's mass and density, then determine its radius using the formula for volume of a sphere) Answer in square light-years.  D) Comparing all above answers, What are the chances (very roughly) that a photon passing through the cloud will hit a dust grain?

icon
Related questions
Question

A) A typical dust grain has a radius of about 0.1 micrometers and a mass of  10-14   grams. Roughly how many dust particles are in a cloud containing 1000 Msun of dusty gas if 1% of the cloud's mass is in the form of dust grains? 

B) What surface area would be covered by these grains if you put them side by side? Assume these grains are spherical. Answer in square light-years.

C) Estimate the total surface area covered by the cloud assuming it's matter density is like that of a typical molecular cloud, about 10-21 g/cm3 (Hint: first calculate the clouds volume from it's mass and density, then determine its radius using the formula for volume of a sphere) Answer in square light-years. 

D) Comparing all above answers, What are the chances (very roughly) that a photon passing through the cloud will hit a dust grain? 

 

Expert Solution
Step 1

Given

Grain radius (R)               = 0.1 micrometers =0.1×10-6 m = 10-7 m

Grain mass (m)               = 10-14   grams = 10-17 kg

Density of the cloud ρ = 10-21 g/cm3

 

 

 

trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps

Blurred answer