Q. 47

Expert-verified
Found in: Page 1115

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# The electron interference pattern of Figure 38.12 was made by shooting electrons with of kinetic energy through two slits spaced apart. The fringes were recorded on a detector behind the slits. a. What was the speed of the electrons? (The speed is large enough to justify using relativity, but for simplicity do this as a nonrelativistic calculation.) b. Figure 38.12 is greatly magnified. What was the actual spacing on the detector between adjacent bright fringes?

(a) The speed of the electron is

(b) The actual distance between consecutive light fringes on the detector is

See the step by step solution

## Step 1: Given information

The kinetic energy of electrons is 50 KeV and a detector captured the fringes is 1.0 m

## Part (a) Step 1: Given information

The electron starts at rest (or close to it), thus the kinetic energy obtained is

## Part (a) Step 2: Finding the electron's speed using kinetic energy

We can begin by calculating the electron's speed using kinetic energy,

## Part (b) Step 1: Given information

On a detector 1.0 m behind the slits, the fringes were recorded

## Part (b) Step 2: Determine the double slit experiment, fringe spacing

In a double slit experiment, we can now utilise an expression for fringe spacing.