Measuring Time and Length
What is Time?
The American Herrtage Dictionary defines time as:
a. A nonspatial continuum in which events occur in apparently irreversible succession from the
past through the present to the future.
b. An interval separating two points on this continuum; a duration: a long time since the last
war; passed the time reading.
c. A number, as of years, days, or minutes, representing such an interval: ran the course in a
time just under four minutes.
d. A similar number representing a specific point on this continuum, reckoned in hours and
minutes: checked her watch and recorded the time, 6:17 a.m.
Put in almost normal words this means that time
a. Only goes in one direction. (Time travel is the stuff of Science Fiction only)
b. Is measured by the 'time' between two points in time. (1pm to 3pm is two hours)
c. Is measured in units like seconds, minutes, hours, etc.
d. The measurement is also called time. (the time is 6:17am, his time for the run was 45sec)
e. Time is measured using the term 'time'.
All this really means is that we need to be very careful when we use the word 'time'.
Definition b is the one we care the most about in this class because we will be
measuring time a great deal. In class seconds and minutes will be used in labs
because our class isn't even 1 hour long (in time).
|Length is a measurement of distance or dimension. The two
main systems to measure length are the metric and the
English system. The metric system is based on 10 as you
can see in the table below. The meter is the standard unit
and portions of that are in tens. You can see the difference
between a centimeter and a millimeter in the picture below.
Always read a ruler in a direct line, not at an angle.
1 centimeter = 0.3937 inches
12 inches = 1 foot
1 inch = 2.54 centimeters
1 foot = 0.3048 meters
3 feet = 1 yard
1760 feet = 1 mile
5280 feet = 1 mile
1 yard = 0.9144 meters
1 meter = 3.28083 feet
1 kilometer = 3281 feet
1 kilometer = 0.6214 miles
3 miles = 1 league
|In this class we will not be doing much
conversion. Mostly because we will be
using all metrics in our measurements.
You can use the chart to the side to get
an idea of how big each measurement is
compared to what you are use to.
|measurement website where you can practice using a centimeter ruler.