Question

(12 points) A positron (mass m and charge +e) moving tow con mass m and charge +e) moving toward a stationary alpha particle (charge +2e). The minimum separation between the particles 15 Imum separation between the particles is d. The only force acting on the particles is the electrical force between them. speed of the positron, when it is at a distance 3d from the alpha particle? b. What happen to the potential energy of the system w to the potential energy of the system when the positron is moved from 3d to d?

Answer 1

Given

Charge of Positron: e

mass of Positron: m

Charge of Alpha particle: 2e

we have to find:

Potential Energy (U_3d): at a distance 3d from charge 2e

Potential energy (U_d):  at a distance d from charge 2e

+20 a particle positron Bd The work done to a distance to taking charge te from 3d from the change the 00 is called defined as u= a re (Valgd - Vool = terre – he Lure. (30) 4086oo) 7 - erre - of L 4re. (30) Und = 2 2² 7 Jule 4080 (30) which is equal to KE Kinetic Energy of positron - me = de 2 Lure (90) N =[402 7/2 Lure, m (3d)] change of e = 1.6 800 lgc, m-9.1x10 31 kg 1 9 xlo une.

v = 4.6 xlo misec. Ans. dh

G Date Date 6 Now moving the charge te from distance 3d to the alistanced towards ch the change the then P.E. urter Vad - Vd) U = te (vd - Vad) Lincod 3 x 4 reod Und [Ud = 2 x Ugd Ans The potential by two times the energy at Ud is increases polential energy Usd.