# Introduction to Physical Science

## Unit 4: Motion and Forces

### Dissect clocks

Introduction:
What time is it? Time for a dissection. Don't worry; you won't need a scalpel for this dissection. In this activity, you will be taking apart a clock to find out how it works. Have you ever wondered how a clock functions? How the hands turn and why the clock will sometimes just stop? In this project you will get to take a clock apart to discover all of the intricate pieces that go into making the clock function.

Break up into small groups:

• One clock per group
• Open the back of the clock
• Diagram the inside of the clock

Create a flowchart that represents the process that takes place inside the clock as the gears turn. In the flowchart, show how the gear position changes with each minute and hour that passes. Also, show the relationship between gear movement and the hands on the clock face. Share your flowchart with the rest of the class and discuss what is happening inside the clock.

Time:
It will take one class period to examine the clock and make a flowchart and a second class period to finish the flowchart and present it to the class.

Possible Resources:
If a clock is not available visit these sites to help you complete this project.

How Pendulum Clocks Work
http://science.howstuffworks.com/clock.htm

How does a pendulum clock work?
http://library.thinkquest.org/C0118228/workclock.htm

A Walk through Time
http://physics.nist.gov/GenInt/Time/revol.html

Inside a wind up alarm clock
http://home.howstuffworks.com/inside-clock.htm

Clock Design
http://www.noah.org/science/clock/