A spring-damper system is designed to support an electric motor which has a total mass of 20 kg and a rotor of 12 kg. Initially, the system has a static deflection of 5 mm after the motor is mounted on the springdamper support, and the center of the rotor is 3 mm misaligned. In free vibration, a displacement of 10 mm is damped to 1 mm in two cycles. Determine the amplitude of the force transmitted to the ground through the spring-damper support system when the motor is operating at 1,200 rpm.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.