A barbell spins around a pivot at its center at A. The barbell consists of two small balls, each with mass 400 grams (0.4 kg), at the ends of a very low mass rod of length d = 25 cm (0.25 m; the radius of rotation is 0.125 m). The barbell spins clockwise with angular speed 80 radians/s. We can calculate the angular momentum and kinetic energy of this object in two different ways, by treating the object as two separate balls, or as one barbell. I: Treat the object as two separate balls (a) What is the speed of ball 1? | | = m/s (b) Calculate the translational angular momentum I trans, 1, A of just one of the balls (ball 1). |[trans, 1, Al = kg m/s O zero magnitude; no direction O into page OO out of page (c) Calculate the translational angular momentum I trans, 2, A of the other ball (ball 2). | Itrans, 2, Al = OO out of page > into page kg m/s O zero magnitude; no direction (d) By adding the translational angular momentum of ball 1 and the translational angular momentum of ball 2, calculate the total angular momentum of the barbell, Itot, A. kg m/s Itot, Al = O zero magnitude; no direction OO out of page O into page (e) Calculate the translational kinetic energy of ball 1. Ktrans,1 m2 = = (f) Calculate the translational kinetic energy of ball 2. Ktrans,2 m2 (g) By adding the translational kinetic energy of ball 1 and the translational kinetic energy of ball 2, calculate the total kinetic energy of the barbell. Ktotal = II: Treat the object as one barbell (h) Calculate the moment of inertia I of the barbell. I = kg m (i) What is the direction of the angular velocity vector ? O zero magnitude; no direction Ointo page O out of page (j) Use the moment of inertia I and the angular speed || = 80 rad/s to calculate the rotational angular momentum of the barbell: kg A. m/s [rotl =1 | | = O into page OO out of page O zero magnitude; no direction m 10 m 2 (k) How does this value, |rotl, compare to the angular momentum | Itot, Al calculated earlier by adding the translational angular momenta of the two balls? Orot = tot, Al Orot] > [tot, Al Orotl Ktotal O Krot = Keotal Additional Materials eBook Submit Answer