# Solving a Probability Question with Griffith's Quantum Mechanics

• chroot
In summary, the probability interpretation in Griffith's Quantum Mechanics assigns probabilities to possible outcomes of quantum mechanical measurements, by squaring the wave function and integrating it over the region of interest. This can be applied in various areas such as solid-state physics, nuclear physics, and quantum chemistry. However, there are limitations to using probability in Griffith's Quantum Mechanics, as it is not applicable to macroscopic objects and cannot predict the exact outcome of a measurement.

#### chroot

Staff Emeritus
Gold Member
Hi there, math geeks. Physics geek here. I came across this problem in Griffith's Introduction to Quantum Mechanics, and just can't decide how to attack it.
A needle of length L is dropped randomly onto a sheet of paper ruled with parallel lines a distance L apart. What is the probability that the needle will cross a line?
I've done the previous problems, but this one just threw me for a loop. Can anyone give me some advice? Thanks!

- Warren

Google for "Buffon's Needle"; you will find plenty.

Thanks for the tip, Ambitwistor!

- Warren

## 1. What is the probability interpretation in Griffith's Quantum Mechanics?

The probability interpretation in Griffith's Quantum Mechanics is a statistical interpretation that assigns probabilities to possible outcomes of quantum mechanical measurements. It states that the square of the wave function gives the probability of finding a particle in a particular location.

## 2. How do you calculate probabilities using Griffith's Quantum Mechanics?

To calculate probabilities using Griffith's Quantum Mechanics, you need to square the wave function and integrate it over the region of interest. This will give you the probability of finding a particle in that region.

## 3. Can Griffith's Quantum Mechanics be used to solve real-world problems?

Yes, Griffith's Quantum Mechanics can be used to solve real-world problems and has been successfully applied in various areas such as solid-state physics, nuclear physics, and quantum chemistry.

## 4. What are some common applications of probability in Griffith's Quantum Mechanics?

Some common applications of probability in Griffith's Quantum Mechanics include calculating the probability of electron transitions in atoms, predicting the behavior of particles in a potential well, and determining the probability of particles tunneling through a barrier.

## 5. Are there any limitations to using probability in Griffith's Quantum Mechanics?

Yes, there are limitations to using probability in Griffith's Quantum Mechanics. It is not applicable to macroscopic objects and is limited to the quantum realm. Additionally, it cannot predict the exact outcome of a measurement, but only the probability of obtaining a certain result.