During operation the jack hammer strikes the concrete surface with a force which is indicated in the graph. To achieve this the 2-kg spike S is fired into the surface at 90 m/s. (Figure 1) Figure F (kN) 1500- S 0 t (ms) 0 0.1 0.4 1 of 1 Part A Determine the speed of the spike just after rebounding. Express your answer to three significant figures and include the appropriate units. v = Value Submit Request Answer Provide Feedback Units