You are at the controls of a particle accelerator, sending abeam of 1.50 * 107 m/s protons (mass m) at a gas target of an unknownelement. Your detector tells you that some protons bounce straight backafter a collision with one of the nuclei of the unknown element. All suchprotons rebound with a speed of 1.20 * 107 m/s. Assume that the initialspeed of the target nucleus is negligible and the collision is elastic.(a) Find the mass of one nucleus of the unknown element. Express youranswer in terms of the proton mass m. (b) What is the speed of the unknownnucleus immediately after such a collision?

You are at the controls of a particle accelerator, sending abeam of 1.50 * 107 m/s protons (mass m) at a gas target of an unknownelement. Your detector tells you that some protons bounce straight backafter a collision with one of the nuclei of the unknown element. All suchprotons rebound with a speed of 1.20 * 107 m/s. Assume that the initialspeed of the target nucleus is negligible and the collision is elastic.(a) Find the mass of one nucleus of the unknown element. Express youranswer in terms of the proton mass m. (b) What is the speed of the unknownnucleus immediately after such a collision?