How many dust particles are in a cloud with 1,000M sun of dusty gas, if 1% of the clouds mass in dust grains?

Question

A typical dust grain has a radius 10^-7 meters and a mass of 10^-4 gram.

Answer 1

The above answerer is on the right track but 10^-4 kg seemed too large for me. 10-4 g is more reasonable and I see is part of the problem. Multiply his/her answer by 10^3, and you might want to do the calculation yourself to double check.

Answer 2

i'm hoping I understood your question properly... Say the cloud has mass M and center of mass placed at C. you are able to divide the cloud into 2 sections, each and each with mass M/2... the branch could be made alongside any open line (or any open floor, for a three-D cloud). The centers of mass A(t) and B(t) of the two sections can pass, yet they are subject to the venture (A(t)+B(t))/2 = C (consistent) from this equation (or via potential of questioning approximately it) you notice that A, B, and C are collinear. Taking the time spinoff: A'(t) + B'(t) = 0 it somewhat is merely the end result that the two sub-clouds ought to have equivalent and opposite velocities -- their momenta ought to sum to 0 to maintain ingredient C table sure. in any different case there is not any restrict on the path of the velocities, by using fact the debris are shifting randomly and no direction is favorite. there will be some danger distribution for the cost of the velocities, based on the particle velocity distribution, yet it is not substantial. Now, attending to angular momentum: if the velocities of the sub-clouds are directed alongside the line ACB then the full equipment has L=0 (vectors CA and CB are parallel to A' and B' so the pass-products vanish). regardless of the shown fact that, if A'(t) has a area orthogonal to A(t) there will be finite angular momentum interior the full cloud. So i might say there is not any reason the cloud don't have finite angular momentum: as you place it, the cloud regularly has a non-0 L, different than interior the specific case that the momenta are directed radially outward. As an aside, i do no longer think of this somewhat explains the superiority of spinning structures in outer area. They spin by using fact they started out with angular momentum. further, if the cloud in this subject has angular momentum, the "reason" is that the equipment started out with it. This subject merely demonstrates that that's a danger for a equipment of randomly shifting debris to have finite angular momentum... type of spectacular, because i might have expected that no direction is favorite whilst the debris are shifting randomly. yet i think the ingredient is that the velocities are distributed randomly contained in right here experience: a particle chosen at random from the full ensemble is the two probable to be shifting in any direction; regardless of the shown fact that, (if the cloud has non-0 L) particle velocity is correlated with place interior the cloud, so as that debris chosen at random from a particular area interior the cloud are *no longer* shifting randomly.

Answer 3

1000 solar masses... 1% of 1000 is 10.

10 solar masses is dust grains. If mass of grain = 10^-4Kg

1 solar mass = 1.98892 × 10^30 kilograms
10 solar mass = 1.98892 × 10^31 kilograms

so 1.98892E+31/1E-4 = 1.98892E+35 Dust Grains