Mathematics · Work and Energy

To evaluate the impact strength of a material, a specimen was used in an Izod impact testing machine. The falling mass is 20 kg and the swing arm is 1 m long. The mass is swung 120° from the lowest vertical point to its release point and released. After impacting the specimen, the mass swings 90° from the lowest vertical point towards the opposite direction. What is the energy absorbed by the specimen? (Take g = 10 m/s2)