Problem SolvingTechniques for solving problems in

physical science

Problem solving

To solve a problem, you use what you already know to figure out something you want to know.

A four step technique

Step 1: Looking For

What is the problem asking for? Figure out exactly what variables or

values need to be in the answer. Example: A 6-gram marble, placed in a

graduated cylinder of water, raises the water from 30 mL to 32 mL. Calculate the marble’s volume and density.› What is the problem asking for?› Volume and density

Step 2: Given What information are you given? Sometimes this includes numbers or

values. Other times it includes descriptive information to interpret.

Example: A 6-gram marble, placed in a graduated cylinder of water, raises the water from 30 mL to 32 mL. Calculate the marble’s volume and density.› What are you given?› The mass of the marble is 6g. The water

level was raised from 30mL to 32mL.

Step 3: Relationships

What relationships exist between what you are asked to find and what you are given?

Example: A 6-gram marble, placed in a graduated cylinder of water, raises the water from 30 mL to 32 mL. Calculate the marble’s volume and density.› The relationship for density mass and

volume is D = m/V.

Step 4: Solution Combine the relationships with what

you know to find what you are asked for.

Once you complete steps 1 through 3, you will be able to see how to solve most problems.

Example: A 6-gram marble, placed in a graduated cylinder of water, raises the water from 30 mL to 32 mL. Calculate the marble’s volume and density.› Volume: 32mL – 30mL = 2mL› Density = 6g/2mL = 3g/mL

Design Problems

Unlike “formula problems,” design problems have many correct solutions limited only by your creativity, ingenuity, skill, and patience.

Example: Create a container that will protect a raw egg from breaking when dropped 10 meters onto a sidewalk.

Useful Steps for Solving Design Problems

1. Write down everything your solution needs to accomplish.

2. Write down every constraint that must also be met. Constraints are limits on cost, weight, time, materials, size, or other things.

3. Think up an idea that might work. Talking with others, doing research, and trying things out are all ways to help.

4. Follow the design cycle.

Design Cycle