A helicopter is using a circular steel cable to lift a m = 2100-kg jeep. The unstretched length of the cable is L = 16 m, and its radius is r = 5.0 x 10-3 m. By what amount does the cable stretch when the jeep is hoisted straight upward with an acceleration of ay = +2.60 m/s?? Young's modulus for steel is Y = 2.0x 1011 N/m2. ay = +2.60 m/s2 (b) Free-body diagram for the jeep (a) The jeep applies a force - F to the lower end of the cable, there by stretching it. (b) The free-body diagram for the jeep, showing the two forces acting on it