PS2_09 - nt-m 2/coul 2 and charge on the electron(or proton...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
2009 Chemistry 118a Problem set #2 Due Friday, September 18 Textbook problems: Ch. 2: 20, 32, 40, 48, 56 Ch. 3: 18, 20, 52, 54, 62 Supplementary problem: In a scattering experiment between alpha particles (helium nuclei) and a thin foil of copper, it was determined that some of the incoming particles moving at an initial speed of 1.6 X 10 7 m/s were completely turned around and “back-scattered”. Let’s analyze this experiment in the context of a single encounter between the alpha particle and a copper nucleus, which we will assume to be rigid. Our goal is to estimate the size of the nucleus from this data. The potential energy for the interaction between two charged particles (with charges Q 1 and Q 2 in units of coulombs) is: where A=9 X 10 9
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: nt-m 2 /coul 2 , and charge on the electron (or proton) has an absolute value of 1.6 X 10-19 coulombs. R is the distance between the two charges in meters. We will assume that the alpha particle is aimed directly at the Cu nucleus. a. Calculate the initial kinetic energy of the alpha particle in joules. b. Graph the motion in this experiment in terms of an initial kinetic energy for the alpha particle encountering the potential energy due to the electrical force of repulsion. c. Calculate the distance between the two particles at the turning point where the alpha particle is reflected back is the opposite direction (remember that’s where the initial kinetic energy equals the potential energy). R Q Q A R U 2 1 ) ( =...
View Full Document

This document was uploaded on 10/25/2011 for the course CHEM 118 at Yale.

Ask a homework question - tutors are online