Chapter 2 Numbers from Measurments

Question 1

Measurement

Answer 1

The determination of the dimensions, capacity, quantity, or extent of something.
Mass, volume, length, time, etc.

Question 2

Exact Number

Answer 2

number that has no uncertainty in it

Question 3

Inexact Number

Answer 3

number that carries a degree of uncertainty. Every measurement has uncertainty to it.

Question 4

Precision

Answer 4

How close a series of measurements are two each other.

Question 5

Accuracy

Answer 5

How close to the true measurement a measurement( or series of measurements) is.

Question 6

Random Error

Answer 6

Error typically generated by some fluctuation in something uncontrollable.

Question 7

Systematic Error

Answer 7

Error originating from controllable variables in an experiment. They are constant. Something such as a flawed piece of equipment

Question 8

Uncertainty

Answer 8

When a measurement is made only one digit is recorded to represent uncertainty. i.e. 15 is uncertain in the ones place, 15.3 is uncertain in the tenths place.

Question 9

Significant Figures

Answer 9

digits in any measurement that are known with certainty plus one digit that is uncertain

Question 10

Human Error

Answer 10

Errors resulting from human limits such as how well a measurement is read or how well a machine is calibrated

Question 11

Instrument Error

Answer 11

Errors originating specifically from the instruments flaws.

Question 12

Rules for Significant Figures

Answer 12

1) All nonzero digits are significant
2) All leading zeroes are insignificant
3) Confine zeroes are always significant
4) Trailing zeroes are only significant if there is a decimal point present

Question 13

Rounding Off

Answer 13

the process of deleting unwanted (non significant) digits from a calculator number

Question 14

Rules for Rounding Off

Answer 14

1) If the first digit to be dropped is less than five then the first sig fig is left the same
2) If the first digit to be dropped is 5 or greater with a nonzero digit after it then the first sig fig is increased by one
3) If the first digit dropped is exactly 5 followed by zeroes or no digits then if the first sig fig is odd raise it. If it’s even leave it be

Question 15

Sig Fig Rule for Multiplication/ Division

Answer 15

the number of sig figs in the product or quotient is the same as the number in the calculation that contains the fewest sig figs.

Question 16

Sig Fig Rules for Addition/ Subtraction

Answer 16

the uncertainty in the answer should be the same as that of the measurement that has the greatest uncertainty. Also remember if a decimal point is present(34.000 = 5 sig figs) than uncertainty is to where the last zero is

Question 17

Order of Magnitude

Answer 17

a signal exponential value of the number 10.

i.e. 10^6 is four orders of magnitude larger than 10^2

Question 18

Multiplication in Scientific Notation

Answer 18

1) multiply coefficients together

2) add the exponents together to get a new power of 10

Question 19

Division in Scientific Notation

Answer 19

1) divide coefficients
2) subtract exponents to get a new power of ten
3) calculator answer must be fixed for sig figs

Question 20

Addition/ Subtraction in Scientific Notation

Answer 20

1) all powers of ten must be the same
2) when exponents are the same coefficients are added/subtracted
3) calculator answer must be fixed for sig figs