1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Rainbow [258]
4 years ago
9

Natural history research involves ____ unobsevable and unrepeatable past events.

Physics
1 answer:
Tanzania [10]4 years ago
4 0
B verifying is the answer
You might be interested in
What is intermolecular forces and how is it related to phases of matter
MakcuM [25]
Intermolecular forces are forces that keep molecules together. For example, the forces between two water molecules. The stronger the intermolecular forces are, the more "solid" is the matter going to be, meaning that the intermolecular forces are the strongest in solids and weakest in gases.
Make sure not to confuse intERmolecular forces (forces between *molecules*) and intRAmolecular forces (forces between *atoms* that make up a molecule).
6 0
3 years ago
DNA’s diameter is 0.000000002 meters. What is this measurement in scientific notation? a. 2.0 x 109 m
NARA [144]

Answer:

0.000000002 m=2.0*10⁻⁹ m

Explanation:

Scientific notation allows us to write very large or very small numbers in abbreviated form. This notation simply consists of multiplying by a power of base 10 with a positive or negative exponent.

A number written in scientific notation has the form:

a*10ⁿ

where:

  • the coefficient a has a value such that 1 ≤ a <10
  • n is an integer.  Represents the number of times the decimal point is shifted. It is always a whole number, positive if it is shifted to the left, negative if it is shifted to the right.

So to write the number 0.000000002 in scientific notation, the following steps are performed:

  • The decimal point is moved to the right as many spaces until it reaches the right of the first digit.
  • This number is then written, which will be the coefficient a in the expression of the previous product. So a=2.0
  • The base 10 is written with the exponent equal to the number of spaces that the comma moves. So n=9. But this is a negative number because the comma shifts to the right.

So, you get: <u><em>0.000000002 m=2.0*10⁻⁹ m</em></u>

3 0
4 years ago
What are some ways in which body fat can be measured
MissTica
I only know about the Water tank which is the most accurate. You place your body in it, and weights are added I think. Somehow some measurements are gathered to get your body fat weight. Online calculators exist, as well as electronic waves that are sent int your body, the echo is recorded and analyzed.
8 0
3 years ago
What is the concentration of H^ + at apH = 2 ? Mol / L What is the concentration of H^ + ions at apH = 6 ? Mol/L How many more H
Nonamiya [84]

Answer:

The concentration of hydrogen ion at pH is equal to 2 := [H^+]=0.01 mol/L

The concentration of hydrogen ion at pH is equal to 6 : [H^+]'=0.000001 mol/L

There are 0.009999 more moles of  H^+ ions in a solution at a pH = 2 than in a solution at a pH = 6.

Explanation:

The pH of the solution is the negative logarithm of hydrogen ion concentration in an aqueous solution.

pH=-\log [H^+]

The hydrogen ion concentration at pH is equal to 2 = [H^+]

2=-\log [H^+]\\

[H^+]=10^{-2}M= 0.01 M=0.01 mol/L

The hydrogen ion concentration at pH is equal to 6 = [H^+]

6=-\log [H^+]\\\\

[H^+]=10^{-6}M= 0.000001 M= 0.000001 mol/L

Concentration of hydrogen ion at pH is equal to 2 =[H^+]=0.01 mol/L

Concentration of hydrogen ion at pH is equal to 6 = [H^+]'=0.000001 mol/L

The difference between hydrogen ion concentration at pH 2 and pH 6 :

= [H^+]-[H^+]' = 0.01 mol/L- 0.000001 mol/L = 0.009999 mol/L

Moles of hydrogen ion in 0.009999 mol/L solution :

=0.009999 mol/L\times 1 L=0.009999 mol

There are 0.009999 more moles of  H^+ ions in a solution at a pH = 2 than in a solution at a pH = 6.

8 0
3 years ago
A particularly beautiful note reaching your ear from a rare stradivarius violin has a wavelength of 39.1 cm. the room is slightl
raketka [301]
The wavelength of the note is \lambda = 39.1 cm = 0.391 m. Since the speed of the wave is the speed of sound, c=344 m/s, the frequency of the note is
f= \frac{c}{\lambda}=879.8 Hz

Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by
f= \frac{1}{2L} \sqrt{ \frac{T}{\mu} }
where \mu=0.550 g/m = 0.550 \cdot 10^{-3} kg/m is the linear mass density of our string.
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
L= \frac{1}{2f}  \sqrt{ \frac{T}{\mu} } =0.31 m
8 0
3 years ago
Other questions:
  • Explain the purpose of a geologic time scale
    10·2 answers
  • In an experiment researchers want to determine if the _____ Variable causes change in _____ variable
    8·2 answers
  • A cube and a square pyramid were joined to form the composite solid. A cube with side lengths of 12 inches. A square pyramid wit
    7·2 answers
  • Which way does the blue arrow on the earth point
    8·1 answer
  • PLEASE HELP PLS ITS DUE IN 10 MINUTES!!
    7·1 answer
  • What does a model of a light wave tell us about<br> brightness and color?
    6·1 answer
  • 1.
    14·2 answers
  • Where is a good place to check your pulse?
    7·2 answers
  • (Score for Question 4: Click or tap here to enter text of 4 points)
    15·1 answer
  • an 8 kilogram ball is fired horizontally form a 1 times 10^3 kilogram cannon initially at rest after having been fired the momen
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!