Privacy and Security Notice

Units and Powers of Ten

IB Physics Summer Lesson 1

Exploring Units and Powers of Ten

This Lesson corresponds to pp. 6-12 in Coletta College Physics.


First, a word on SI, or Systeme International...

The basic metric system is called SI but in most of physics we will deal with two subsets of that:
  • The MKS -- meters (m), kilograms (kg), seconds (s) -- system
  • The cgs -- centimeters (cm), grams (g), seconds (s) -- system

    Each refers to base units of length, then mass, then time.

    Exercises: Grab a ruler and your textbook. Measure, calculate (where appropriate), and record the following...
    1. The length, width, and height of your text in (A) cm, (B) m, and (C) inches.
    2. Divide each dimension in cm by the same dimension in m (e.g. length in cm divided by length in m). Do you get a consistent result? What is it?
    3. Divide each dimension in inches by the same dimension in cm (e.g. length in inches divided by length in cm). Do you get a consistent result? What is it?
    4. How would you convert 200 m to cm? to inches? Both describe how you would do it and give an answer.
    5. Find the area of the front of the book in square meters (m2) and in square cm (cm2). Recall that A=LW.
    6. Divide the area in cm2 by the area in m2. What do you get? What relationship does this seem to have to the cm-m conversion factor you found in question 2?
    7. Find the volume of the book in cubic meters (m3) and in cubic cm (cm3, equivalent to milliliters, or mL). Recall that V=AH = LWH.
    8. Divide the volume in cm3 by the volume in m3. What do you get? What relationship does this seem to have to the cm-m conversion factor you found in question 2?
    9. If there are 1000 (or 103) mL in a liter, how many liters are in a m3?
    10. Find the best way to graph the size in meters (horizontal axis) vs. the mass of the various objects in the table below. Keep the graph to show later. When you e-mail in your answers, simply describe the graph and how you made it.

      Object Size in m Mass in kg
      up quark 10-19 10-29
      electron 10-18 10-30
      proton 10-15 10-27
      helium atom 10-10 10-26
      Mr. Cecire 100 102
      Earth 107 1025
      Solar System 1013 1030


    Please e-mail all answers to Mr. Cecire at cecirek@yahoo.com.
    Due Date: July 1, 2000

    RETURN TO MAIN PAGE