An alpha particle is a nucleus of helium. it has twice the charge and four times the mass of the proton. when they were very far away from each other, but headed toward directly each other, a proton and an alpha particle each had an initial speed of 8.5e-3c, where c is the speed of light. what is their distance of closest approach? there are two conserved quantities. make use of both of them. (c = 3.00

Explanation:

By energy conservation we know that initially when both are far apart from each other then in that case total electrostatic kinetic energy of two charges will convert into electrostatic potential energy of two charges

so we have

now we know that there is no external force on this system so momentum is conserved here

now plug in all values in first equation

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.