physical science ch 2. standard – exact quantity that people agree to use for comparison purpose -...
TRANSCRIPT
Standard –
Exact quantity that people agree to use for comparison
Purpose - When all measurements are made with same standard, measurements can be compared
Measurement system –
English
Metric- multiples of 10
International System of Units - 1960
CHAPTER 2
-Units of measurement and standards-Length -Mass-Time -Temperature-amount of a substance (atoms/molecules)-Electrical current-luminosity
-3 types of graphs
LENGTH
-The distance between two points
SI Base Unit = meterSI is based in powers of ten:-deci- means 1/10-centi- means 1/100
100 cm = 10 dm = 1 m
USING MATH
How many centimeters are in 1.98 meters?
Problem-Solving Steps:
1. What is known? 1 m = 100 cm
2. When converting from larger units (m) to smaller (cm) you multiply
VOLUME
-The amount of space occupied by an object
-If length, width, and height are expressed in centimeters, then volume (length x width x height) is expressed in: cm3 “cubic centimeters”
-No tool can measure volume, so combine 2 SI Units (refer to p 38)….
-Volume units are derived units;
- 1 Liter = 1 cubic decimeter (dm3)
MASS
A measurement of matter in an object
SI unit is kilogram (kg).
For objects of small mass, grams (g) or milligrams (mg) are used
Convert from g to kg, etc.
DENSITY
-Like volume, density is a derived unit
-Mass per unit volume, or mass/volume (g/mL)
-Each material has its own unique density
TEMPERATURE
The amount of thermal energy (heat) in a substance.
**For now, think of temperature as “how hot or cold something is”
-Temperature is measured on the Celsius (c) scale-Water at freezing = 0 degrees C; water at boiling
= 100 degrees C-SI Unit is Kelvin (K) = NO DEGREE SIGN!!; find
Kelvin by adding 273 to the Celsius temperature
2.3: GRAPHS
Line Graphs: ‘
-used to show trends or how data changes over time
- What information is shown here?
GRAPHS
Bar Graphs:
- Useful for comparing information collected by counting
- Height corresponds to a number of (y)
- This bar graph shows…?
IMPORTANCE OF GRAPHS
- A visual display of informationor data- Who uses graphs?
- Businesses- Sports, sport agents, coaches- Economics- Politics- Engineering- Science and research- ???Anyone else???