In one of the classic nuclear physics experiments at the beginning of the 20th century, an alpha particle was accelerated towards a gold nucleus and its path was substantially deflected by the Coulomb interaction. If the initial kinetic energy of the doubly charged alpha nucleus was 5.17 MeV, how close to the gold nucleus (79 protons) could it come before being turned around? (m)

(a) What is the electric potential energy of two electrons separated by 1.75 nm? (b) What would be it be if the separation was doubled? (a) Number (b) Number i Units Units

A proton is located at the origin, and a second proton is located on the x-axis at x1 = 6.22 fm (1 fm = 10−15 m). (a) Calculate the electric potential energy associated with this configuration. J (b) An alpha particle (charge = 2e, mass = 6.64 ✕ 10−27 kg) is now placed at (x2, y2) = (3.11, 3.11) fm. Calculate the electric potential energy associated with this configuration. J (c) Starting with the three particle system, find the change in electric potential energy if the alpha particle is allowed to escape to infinity while the two protons remain fixed in place. (Throughout, neglect any radiation effects.) J (d) Use conservation of energy to calculate the speed of the alpha particle at infinity. m/s (e) If the two protons are released from rest and the alpha particle remains fixed, calculate the speed of the protons at infinity. m/s

Two protons are released from rest 15 mm apart. (A) describe the subsequent motion after they are released.(B) how fast are the protons moving when they are a great distance apart Give the answer if the initial separation is 14 mm