I need help with part e

The Charpy impact tester can be used to determine the type of fracture of a material and the fracture energies (see lecture notes L26 and embedded video). (a) In an impact test of specimen A, the initial height of a hammer of 5.0kg weight was 1.2m and the final height 0.2m. What was the approximate impact energy onto the sample? (b) In an impact test of specimen B, the same conditions were used. The initial height of the hammer was 1.2m and the final height 0.8m. What was the approximate impact energy onto the sample? (c) In an impact test of specimen C, the same conditions were used. The initial height of the hammer was 1.2m and the final height 0.4m. What was the approximate impact energy onto the sample? (d) What was the initial energy of the hammer in all cases? Which sample had the highest toughness? (e) The three standardized samples A, B, and C were a semicrystalline polymer (polystyrene) with a yield strength of 42MPa, window glass with a yield strength of 55MPa, and a copper alloy with a yield strength of 60MPa. Using the data from the Charpy test, identify the likely material each sample consists of and explain your choice