Lesson: Rutherford Scattering Physics • 9th Grade

In this lesson, we will learn how to calculate the distance of closest approach between two charged objects by considering energy conservation.

Lesson Plan

Students will be able to

recall that Rutherford scattering is the elastic scattering of charged particles via the Coulomb interaction,
identify in diagrams which particles would be scattered the most and the least based on their paths,
understand how the initial speed and direction of motion of the incident particle affect how much it is deflected by,
use the kinetic energy of the incident particle to determine how close it will get to the target particle, using .

Lesson Video

Lesson Worksheet

Q1:

An alpha particle is fired with an initial speed of 800 m/s directly toward a fully ionized carbon nucleus that is stationary and cannot move.

What is the initial kinetic energy of the alpha particle? Use a value of kg for the mass of an alpha particle. Give your answer in scientific notation to two decimal places.

What is the distance of closest approach of the alpha particle to the carbon nucleus? Give your answer to two decimal places.

Q2:

A proton is fired with an initial speed of 150 m/s directly toward a fully ionized lithium nucleus that is stationary and cannot move. What is the distance of closest approach of the proton to the lithium nucleus? Use a value of kg for the mass of the proton. Give your answer in scientific notation to two decimal places.

Q3:

A proton is fired with an initial speed of 100 m/s directly toward another proton that is stationary and cannot move.

What is the initial kinetic energy of the first proton? Use a value of kg for the mass of a proton. Give your answer in scientific notation to two decimal places.

What is the distance of the closest approach of the first proton to the second? Give your answer in scientific notation to two decimal places.