8. A motor shaft rotates at 125.66 r/s. What is the rotational speed in rpm? A. 1200 rpm B. 20 rpm C. 7540 rpm D. 789.5 rpm 9. A weight on the end of a 20cm piece of string is spun at 30 rpm. What is the linear velocity of the weight? A. 6 m/s B. 0.377 m/s C. 0.628 m/s D. 62.8 m/s E. None of the above 10. If the string in question #9 above speeds up to 60 rpm in 15 seconds, what is the angular acceleration during that time? A. 0.209 r/s2 B. 4 r/s2 C. 0.067 r/s2 D. 0.25 r/s2 E. None of the above