## Problem Solving in Physics

by April Atkin
## 1. Conservation of Energy

### 1.1. Energy is usually conserved. Carefully note what kinds of energy you start and finish with and make them equal to each other.

## 2. Conservation of Momentum

### 2.1. Are there any eternal forces?

2.1.1. Yes

2.1.2. No

2.1.2.1. Great! Momentum is conserved, so final momentum=initial momentum!

### 2.2. Are there any eternal torques?

2.2.1. No

2.2.1.1. Great! Angular momentum is conserved! Initial=final.

2.2.2. Yes

## 3. Formulas

### 3.1. Check your formula sheet - are there any formulas that have the variables you need to solve this problem?

## 4. Trig Identities

### 4.1. Solving a triangle? Use SOH CAH TOA to find unknown quantities

## 5. Sum of the Forces

### 5.1. Remember, the Sum of the Forces F=ma - if there is no acceleration, there is no net force!

### 5.2. This works for the sum of the torques too. The sum of the torques =I(alpha)