How to Solve Physics Problems
What is problemsolving?
General ProblemSolving Strategy
Step 1: Identify what’s being given
Step 2: Clarify what’s being asked.
If necessary, rephrase the question
Step 3: Select a strategy
Trial & error, search, deductive reasoning, knowledgebased, working backwards
Step 4: Solve using the strategy
Step 5: Review the answer
Example:
Determine the relationship between force of friction and the coefficient of friction
Step 
Description 
Information 
1 
Identify what’s given 
Force of friction and coefficient of friction 
2 
Identify what’s asked 
How they relate 
3 
Strategy: Deductive reasoning 
Force of friction is found with the equation: F_{f }= mF_{N}
m is the coefficient of friction and is a measure of the roughness of the two surfaces. 
4 
Apply the strategy 
As roughness increases, there is more friction.
If m is the measure of the roughness of the surfaces, then as the roughness increases the m increases.
m and friction are directly related. 
5 
Review the solution 
The mathematic formula matches the reasoning. 
Using symbols with mneumonics:
 When writing symbols in physics, use a mneumonic to help you remember what the symbol is representing.

 e.g. For mass of proton, use “mp” and for velocity of car and truck use “Vc” and “Vt” rather than “V1” and “V2”
KUDOS Method
Use the KUDOS method for solving word problems.
 K = Known
 U = Unknown
 D = Definition
 O = Output
 S = Substantiation
Tips for KUDOS steps
 K (Known)
Use units to indetify information
Write information symbolically
Look for implied information
Write out chemical equations
 U (Unknown)
What is the problem looking for?
Write information symbolically
 D (Definition)
Find equalities to conver
Choose & Rearrange equations
Look for missing information in other places
If you cannot find enough information, reevaluate your plan
 O (Output)
Plug in values to the equations (use constants as needed)
Check unit cancellation & perform the calculation
 S (Substantiation)
Check validity of your answer
Check units
Check signficiant figures
 Example:
 What is the change in velocity if the initial velocity is 23 m/s and the final velocity is 15 m/s?
Step 
Source Information 
Write down 
K 
Initial velocity 
V0 = 23 m/s 
Final velocity 
V1 = 15 m/s 
U 
What is the change in velocity 
DV = ? m/s 
D 
Change in equation 
DV = V1 – V0 
O 
Output of the equation 
DV = V1 – V0
DV = 15 m/s – 23 m/s
DV = 8 m/s 
S 
Substantiation 
8 m/s atm is reasonable for velocity
“m/s” is the pressure unit given in the problem.
0 decimal places given 0 in answer 
Exam prep tips
 Stay ahead of the game
 Make a cheatsheet
 Know the format of the test and information that’s fair game
 Make a mock exam
 Attend the review session
 Get help early
Exam taking tips
 Arrive early and prepared
 Listen & Read instructions carefully
 Memory dump first
 Skim the test and form a plan
 Answer questions sequentially
 Apply the guessing rule
 Multiplechoice tips:
 Scan all the choices
 Avoid word confusion
 Beware of absolutes
 Essay tips:
 Understand the question
 Answer the whole question and only the question
 Watch your time
 FreeRepsonse tips:
 Show partial work
 Don’t forget units
 Don’t be fooled by blank space
