3. Science Stuff Flashcards
Physics
The study of the nature of matter and energy and its interactions in the fields of mechanics (kinematics and dynamics), electricity and magnetism, waves (light-optics & sound-acoustics), fluids, heat, atomics structure, and nuclear structure (including radiation).
The Measures of Science
- Qualitative Measurements 2. Quantitative Measurements
Qualitative Measurements
Observations that involve no measurements or units.
Quantitative Measurements
Observations that involve measurements or numbers w/ units.
Scientific Notation aka (Exponential)
To make it easy to calculate by writing a scientific notation(1x1012m)instead of a long form like 1,000,000,000,000 m.
What are the steps to do the Scientific Exponential Notation?
- Rewrite # by moving the decimal place to make a number greater than or equal to 1 land less than 10. (e.g., 123456789 or 8.9/9.6/ etc.)
- Place a “x10–” and count how many decimal places you moved the decimal to achieve step 1.
- If the number was originally greater than 1 write the number of decimals counted in step 2 in the blank of step 2.
- If the nu,ber was originally less than 1 write the number of ecimals counted in step 2 in the blank of step 2 but put a - in front of it to indicate this.
Simplify to a scientific notation.
100
1x102
Simplify to a scientific notation.
0.005
5x10-3
Simplify to a scientific notation.
443.2
4.432x102
Simplify to a scientific notation.
299,790,000
2.9979x108
Simplify to a scientific notation.
0.000054
5.4x10-5
Significant Digits in Measurements
The valid digits in measurement aka sig figs (significant figures)
Rules for determining the number of significant figures in a measurement.
- Non zero numbers are always significant.
(e. g., 2.84 km = 3 sig figs// 1.87x = 3 sig figs) - All final zeros after a decimal point are significant.
(e. g., 7.360 s = 4 sig figs// 75.0 kg = 3 sig figs) - Leading zeros used solely as place holders are not significant.
(e. g., 0.00345 = 3 sig figs// 0.023 = 2 sig figs) - Zeros between two other significant digits are always significant.
(e. g., 2804 m = 4 sig figs// 0.003086 = 4 sig figs) - Zeros located at the end of a number & to the left of a decimal point MAY BE significant (need to look at what the accuracy is)
(e. g., 20C (accurate to the ones place) = 2 sig figs//
2000 kg (accurate to the tens place) = 3 sig figs.)
What to Remember in Arithmetic with Significant Figures
The result can never be more precise than the least precise number.
Rules of Arithmetic with Significant Figures
Rule #1: Addition and Subtraction
To add or subtract measurements, first perform the operation, then round off the answer to last decimal place of the least precise measurement.
e. g., 24.686 m + 2.341 m + 3.2 m = 30.2 (30.227)
2. 456 s - 0.03 = 2.43 (2.426)
Rule #2: Multiplication and Division
A different rule governs multiplication and division. After performing a calculation, note the measurement with the smallest number of significant figures and round your final answer to this number of significant figures.
- 22cm x 2.1cm = 6.8 (6.762)
- 5m/3.414 = 10.7 (10.6912712360867)
Significant Figures when Taking Measurements
When recording measurements taken during an experiment, you must always record them with the correct number of significant figures based on the tool for measuring. OR THE ROCKET WILL EXPLODE!
Converting to base unit formula
Measurement in original unit x Multiplier New Unit
1 Multplier Original Unit
This is equal to Measurement with new Units
The precision of measurement is
how well several measurements of the same quantity agree.
The accuracy of the measurement is…
how well several measurements are correct.
Percent Error
Is a means to quantify the accuracy of our measurements. Percent error less than 20% is considered accurate.
Percent error formula
Percent Deviation
is a means to quantify the precision of our measurements. Percent deviation less than 20% is considered precise.
Percent deviation formula
