PRACTICE IT A wheel rotates with a constant angular acceleration of 3.20 rad/s". Assume the angular speed of the wheel is 1.75 rad/s at 1; = 0. (a) Through what angle does the wheel rotate between ? = 0 and : = 2.00 s? Give your answer in radians and revolutions. rad rev (b) What is the angular speed of the wheel at ? = 2.00 s? rad/s (c) What angular displacement (in revolutions) results while the angular speed found in part (b) doubles? rev EXERCISE HINTS: GETTING STARTED | I'M STUCK! Use the values from PRACTICE IT to help you work this exercise. (a) Find the angle through which the wheel rotates between z = 2.00 s and / = 3.30 s. rad (b) Find the angular speed when t = 3.30 s. rad/s (c) What is the magnitude of the angular speed four revolutions following ? = 3.30 s? rad/s Need Help? Read ItPRACTICE IT 3. A compact disc rotates from rest up to an angular speed of 31.3 rad/s in a time of 0.880 s. (a) What is the angular acceleration of the disc, assuming the angular acceleration is uniform? rad/s2 (b) Through what angle does the disc turn while coming up to speed? 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. m/s (d) What is the magnitude of the tangential acceleration of the microbe at the given time? m/s2 EXERCISE HINTS: GETTING STARTED | 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 0.250 s after it begins to rotate? @ = rad/s 40 = rad (b) Find the tangential speed at the rim at this time. m/s Need Help? Read ItPRACTICE IT A race car accelerates uniformly from a speed of 35.0 m/s to a speed of 64.0 m/s in 5.00 s while traveling clockwise around a circular track of radius 3.90 x 102 m. When the car reaches a speed of 50.0 m/s, find the following. (a) the magnitude of the centripetal acceleration m/s (b) the angular speed rad/s (c) the magnitude of the tangential acceleration m / s 2 (d) the magnitude of the total acceleration m / s 2 EXERCISE HINTS: GETTING STARTED | I'M STUCK! Use the values from PRACTICE IT to help you work this exercise. Suppose the race car now slows down uniformly from 64.0 m/s to 33.0 m/s in 4.20 s to avoid an accident, while still traveling a circular path 3.90 x 10 m in radius (a) Find the magnitude of the centripetal acceleration when the speed is 40.0 m/s. m / s 2 (b) Find the angular speed when the speed is 40.0 m/s. rad/s (c) Find the magnitude of the tangential acceleration when the speed is 40.0 m/s. m/s (d) Find the magnitude of the total acceleration when the speed is 40.0 m/s. m/s 2 Need Help? Read It Submit AnswerPRACTICE IT Use the car travels at a constant speed of 29.0 mi/h (13.0 m/s) on a level circular turn of radius 44.0 m, as shown in the bird's-eye view in figure a. What minimum coefficient of static friction, #,, between the tires and the roadway will allow the car to make the circular turn without sliding? EXERCISE HINTS: GETTING STARTED | I'M STUCK! At what maximum speed can a car negotiate a turn on a wet road with coefficient of static friction 0.205 without sliding out of control? The radius of the turn is 24.0 m. m/s Need Help? Read ItLEARN MORE REMARKS In fact, both banking and friction assist in keeping the race car on the track. QUESTION What three physical quantities determine a minimum and maximum safe speed on a banked racetrack? (Select all that apply.) O the coefficient of kinetic friction between the tires and the road surface the mass of the vehicle O the angle the road surface makes from the horizontal O the radii of the curves O the weight of the vehicle O the coefficient of maximum static friction between the tires and the road surface EXERCISE HINTS: GETTING STARTED | I'M STUCK! A racetrack is to have a banked curve with radius 270 m. What should be the angle of the bank if the normal force alone is to allow safe travel around the curve at 57.0 m/s? Need Help? Read It