`10^(18)` electrons hit a target per second in a X-ray tube with a velocity of `2 xx 10^(6) m cdot s^(-1)`. The mass of the metallic piece of the target is 200 g, specific heat is `0.12 cal cdot g^(-1) cdot^(@)C^(-1)` and mass of an electron is `9.1 xx 10^(-28) g`. If 98% of the energy is converted into heat, how much time will be required to increase the temperature of the metallic piece of the target by `50^(@)C`?

Answer

47 min