Q1. A 44.20 cm diameter disk rotates with a constant angular acceleration of 2.84 rad/s2. It starts from rest at t = 0, and a line drawn from the center of the disk to a point P on the rim of the disk makes an angle of 57.3° with the positive x-axis at this time.
(a) Find an angular speed of the wheel at t = 2.30 s.
(b) Find a linear velocity and tangential acceleration of P at t = 2.30 s.
(c) Find a position of P (in degrees, with respect to the positive x-axis) at t = 2.30s.
Q2. Two ice-skaters, whose masses are 50 kg and 80 kg, hold hands and rotate about a vertical axis that passes between them, making one revolution in 2.50 s. Their centers of mass are separated by 1.70 m, and their center of mass is stationary. Model each skater as a point particle.
(a) Find an angular momentum of the system about its center of mass.
(b) Find a total kinetic energy of the system.