An amusement park ride consists of airplane-shaped cars attached to steel rods (Fig. 11.63). Each rod has a length of 15.0 m and a cross sectional area of 8.00 cm2€¢
(a) How much is the rod stretched when the ride is at rest? (Assume that each car plus two people seated in it has a total weight of 1900 N)
(b) When operating, the ride has a maximum angular speed of 8.0 rev/min. How much is the rod stretched then?