PRACTICE IT Use the worked example above to help you solve this problem. A compact disc rotates from rest up to an angular speed of 32.1 rad/s in a time of 0.853 s. (a) What is the angular acceleration of the disc, assuming the angular acceleration is uniform? 37.63 rad/s2 (b) Through what angle does the disc turn while coming up to speed? 13.69 rad (c) If the radius of the disc is 4.45 cm, find the tangential speed of a microbe riding on the rim of the disc. 1.428 m/s (d) What is the magnitude of the tangential acceleration of the microbe at the given time? 1.67 m/s2 EXERCISE HINTS: GETTING STARTED I I'M STUCK! Use the values from PRACTICE IT to help you work this exercise. (a) What are the angular speed and angular displacement of the disc 0.270 s after it begins to rotate? W = rad/s AO = rad (b) Find the tangential speed at the rim at this time. m/s
