Estimate the luminosity of a 1 solar mass protostellar cloud, which collapses from an initial radius of 10^3 au down to a solar radius, over a timescale of 40 million years by radiation of its gravitational potential energy, in the units of the present solar luminosity:

The electronic structure or chlorine is 2.8.7 what is the electronic structure of fluorine?

Agraduated cylinder contains 63.0 ml of water. a piece of gold, which has a density of 19.3 g/ cm3, is added to the water and the volume goes up to 64.5 ml. calculate the mass in grams of the gold that was added to the water. explain how you got your answer.

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.