Ask question

Ask question

All categories

3 years ago

9

Scientific theories are explanations for scientific phenomena that can be changed when and if new information is found to suppor

t or refute the explanation. Which of the following statements provides an example of a scientific theory?. a.. An object at rest will remain at rest unless acted on by an outside force.. b.. Species evolve by passing on advantageous hereditary traits.

1 answer:

MatroZZZ [7]3 years ago

3 0

"An object at rest will remain at rest unless acted on by an outside force" is the one statement among the following choices given in the question that provides an example of a scientific theory. The correct option among the two options that are given in the question is the first option or option "a". I hope the answer helped you.

You might be interested in

Complete each sentence with the correct type of lens.

andrey2020 [161]

Answer:

Convex and Concave

Explanation:

Took test.

6 0

3 years ago

To understand the decibel scale. The decibel scale is a logarithmic scale for measuring the sound intensity level. Because the d

frez [133]

The question is incomplete. Here is the complete question.

To understand the decibel scale. The decibel scale is a logarithmic scale for measuring the sound intensity level. Because the decibel scale is logarithmic, it changes by an additive constant when the intensity when the intensity as measured in W/m² changes by a multiplicative factor. The number of decibels increase by 10 for a factor of 10 increase in intensity. The general formula for the sound intensity level, in decibels, corresponding to intensity I is

$\beta=10log(\frac{I}{I_{0}} )dB$ ,

where $I_{0}$ is a reference intensity. for sound waves, $I_{0}$ is taken to be $10^{-12} W/m^{2}$ . Note that log refers to the logarithm to the base 10.

Part A: What is the sound intensity level β, in decibels, of a sound wave whose intensity is 10 times the reference intensity, i.e. $I=10I_{0}$ ? Express the sound intensity numerically to the nearest integer.

Part B: What is the sound intensity level β, in decibels, of a sound wave whose intensity is 100 times the reference intensity, i.e. $I=100I_{0}$ ? Express the sound intensity numerically to the nearest integer.

Part C: Calculate the change in decibels ( $\Delta \beta_{2},\Delta \beta_{4}$ and $\Delta \beta_{8}$ ) corresponding to f = 2, f = 4 and f = 8. Give your answer, separated by commas, to the nearest integer -- this will give an accuracy of 20%, which is good enough for sound.

Answer and Explanation: Using the formula for sound intensity level:

A) $I=10I_{0}$

$\beta=10log(\frac{10I_{0}}{I_{0}} )$

$\beta=10log(10 )$

β = 10

<u>The sound Intensity level with intensity 10x is </u><u>10dB</u>.

B) $I=100I_{0}$

$\beta=10log(\frac{100I_{0}}{I_{0}} )$

$\beta=10log(100)$

β = 20

<u>With intensity 100x, level is </u><u>20dB</u>.

C) To calculate the change, take the f to be the factor of increase:

For $\Delta \beta_{2}$ :

$I=2I_{0}$

$\beta=10log(\frac{2I_{0}}{I_{0}} )$

$\beta=10log(2)$

β = 3

For $\Delta \beta_{4}$ :

$I=4I_{0}$

$\beta=10log(\frac{4I_{0}}{I_{0}} )$

$\beta=10log(4)$

β = 6

For $\Delta \beta_{8}$ :

$I=8I_{0}$

$\beta=10log(\frac{8I_{0}}{I_{0}} )$

β = 9

Change is

$\Delta \beta_{2},\Delta \beta_{4}$ , $\Delta \beta_{8}$ = 3,6,9 dB

6 0

3 years ago

Savanna regions developed during the Triassic period.

stich3 [128]

The answer is : true

5 0

1 year ago

A 1,800-kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 3.00 m before coming into contact

Jobisdone [24]

Answer:

average force = 385,140 N

Explanation:

from the question we are given the following

mass (m) = 1800 kg

distance of fall (d) = 3 m

driven distance (l) = 14.4 cm = 0.144 m

acceleration due to gravity (g) = 9.8 m/s^{2}

work done = average force x driven distance.....equation 1

and

work done = change in kinetic energy + change in potential energy

work done = (0.5 x m x (v^{2} - u^{2})) + (m x g x (-d-l))

Initial velocity (u) and final velocity (v) are zero because the pile driver is it rest before it moves to hit the pile and after hitting the pile.
The changes in length for the potential energy are negative because the pile moves downward

we now have work done = (m x g x (-d-l))...equation 2

now equating the two equations for work done we have

average force x driven distance = (m x g x (-d-l))

average force x 0.144 = 1800 x 9.8 x (-3-0.144)

average force = (1800 x 9.8 x (-3-0.144)) ÷ 0.144

average force = 385,140 N

3 0

3 years ago

Which statement describes a property of a proton?

lesantik [10]

Answer:

They have no charge and are present in the nucleus of an atom. They have a negative charge and travel around the nucleus of an atom. They have a positive charge and travel around the nucleus of an atom

Explanation:

7 0

3 years ago