1. Star formation Consider a gas cloud in the Galaxy that might collapse to form stars. Its physical parameters are the mass density p (mass/volume), the sound speed c. (length/time). Gravity is important so we need to introduce Newton's constant G as well. Use dimensional analysis to write down a symbolic order-of-magnitude estimate for each quantity listed. Then, evaluate it using values char- acteristic of star-forming regions within dense interstellar clouds: p = 2 10 19 g/cm and c, = 2 10 cm/s x 0.2 km/s. Please report an- swers in astronomy units:2 Solar masses (M = 2.0 1033 g), parsecs (pc=3.1 x 1018 cm), and millions of years (Myr = 3.2 1013 s). x (a) T, a characteristic dynamical time (b) R, a characteristic length scale (c) M, a characteristic mass = (d), a characteristic mass per unit length (e) M, a characteristic mass growth rate