1. The problem statement, all variables and given/known data A molecular cloud 0.2 light years across rotates once every 1.4 ×107 years. If it were to collapse to the size of our Sun, how long would it take to rotate once if it conserved angular momentum given by mvr, where m is mass, v is the circular rotation speed and r is the radius. Is this reasonable in this case? 2. Relevant equations l=mvr 3. The attempt at a solution the suns rotation is approx 26.8 days the radius i worked out to be 0.1 x 9.4605284 × 10^15 metres = 9.4605284 x 10^14 metres rotation= 1.4 x 10 ^7 years do i also use the mass of the sun? in which case m=1.99 x 10^30 kg? then sub into l=mvr ?