Q.2.3 A tensile test piece is prepared from a material where the diameter of the testpiece was 12 mm and the gauge length was 50 mm. This sample was deformed intially at a rate of 1 mm/sec, The force has increased gradually and reached a value of 47500 N when the gauge length was 55 mm. Then all of a sudden the rate was increased to 20 mm/sec. As a result the force has increased to 47800 N. Then a) Sketch the force-displacement curve depicting the experiement above. b) What is the true stress when the rate of displacement was increased, just before the increase and justy after the increase c) What is the value of m,( i.e. rate sensivity index) in this material