A copper wire of diameter 0.80 mm fails at an engineering stress = 248.2 MPa. Its ductility is measured as 75% reduction of area. Determine the true stress and true strain at failure.

Aball with a mass of 1.5 kilograms is tied to the end of a rope. the ball is pulled to a height of 0.5 meters above the ground and released. the ball has joules of potential energy at position b. at position a, all of the energy changes to kinetic energy. the velocity of the ball at position a is meters/second. assume there’s no air resistance.