measurements

Question 1

define precision

Answer 1

degree of agreement between repeated measurements of the same quantity

Question 2

define accuracy

Answer 2

closeness of the mean value of data collected to that of the original value

Question 3

define systematic error

Answer 3

error that results in readings being always above or always below the true value by a fixed amount

Question 4

define random error

Answer 4

measurements being scattered about a mean value with an equal probability of being positive or negative

Question 5

what causes systematic error (there are 2)

Answer 5

1. Not accounting for zero error
2. Not accounting for background radiation

Question 6

what causes random error

Answer 6

1. human error
2. inconsistency in collecting data

Question 7

how to reduce random error

Answer 7

1. repeat exp 3 times and calculate average
2. plot line of best fit

Question 8

how to calculate uncertainty

Answer 8

1. upperbound method:

uncertainty = (Qmax -Qmin)/2

2. if term comes in this form: Q= aX + bY / aX - bY

then uncertainty is = |a|* uncertainty value of X + |b| * uncertainty value of Y

if term comes in the form Q= ax^m x y^n or Q= a(x^m/y^n)

then uncertainty of Q (abs uncertainty) = |m|* uncertainty value of x/ value of x + |n| * uncertainty value of y / value of y

Question 9

what is the sf of absolute uncertainty

Answer 9

1sf

Question 10

how to calculate percentage uncertainty

Answer 10

( uncertainty of x / value of x ) * 100

Question 11

sf of percentage uncertainty

Answer 11

2sf