DEFINITIONS
A comparison of an unknown quantity to a known standard unit.
measurement
What is 367000 grams in kilograms
367
4
Meter
What are the basic steps in solving a problem
1) write what you know
2) Write the formula and solve for the unknown
3) Plug in
4) Estimate and calculate
5) Check
6) Record the answer
How many significant figures in 25 quarters.
none
dimension
Convert 6791 kg to mg and report answer in scientific notation.
6791*1000*1000= 6.791x10^9
How many significant figures are in 0.000607080
6
SI unit for liquid
liter
What factors affect the precision in measurements
math error
improper calibration
procedural error
How does one add numbers and consider significant figures?
"Round" to the smallest place value.
DAILY DOUBLE
The widely used method of measurement needed to quantify data in the world around us is the
Another name for it is .....
metric system
-another name: SI
16 mm * (1 cm/10mm)
Perform the following operation:
12.3g - 4.67g - 0.00021g
Answer with correct sig/fig 7.6g
(7.62979g )
The SI unit for particles in a substance
mole
Something has volume of 45mL and a mass of 3.56g. What is the density?
45 x 3.56= 160.2 g/mL
In significant figures: 1.60 x 10^2 g/mL
When determining significant figures in multiplication and division problems, the answers can not contain more significant figures than the measurement with the least significant figures
True
Two essential parts of a measurement
a number and the unit of measurement
Convert from kilometers per hour to meters per second
multiply by 1000m/1km* 1k/60min * 1 min/60 sec
How many significant digits in 0.0043
two
What are two benefits of SI
--only one measurable unit for each dimension
--SI units are based on physical constants
--SI is a decimal system and can be scaled by units of 10
What is the formula for density?
density = mass / volume
What is accuracy
The numerical evaluation of how close a measured value is the the expected value
You measure the mass of a substance and get 67.2g, 67.16g, 67.21g. The actual mass is 67.19. In terms of accuracy and precision, the measurements are?
accurate and precise
Perform the following calculation. Provide the answer in meters.
(45.3cm)* (3.0m)
1.4 (because of sig fig)
34.3* 3.0 = 1.359
Significant figures apply only to what type of data?
measured
(you do NOT do sigfigs with counted or pure numbers)
Length: meter
Mass: kilogram
Time: second
Temperature: Kelvin
Number of particles: MOLE
Electric Current: Amp
Light Intensity: Candela
How do you calculate % error?
How do you calculate absolute error?
{(value measured- value of accepted)/ value of accepted } * 100
{|value measured- value of accepted|/ value of accepted } * 100
What is precision
How close numbers are to each other