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2 years ago

Statements best explains why a scientific theory can be revised?

1 answer:

4 0

Answer: Because new theories can come out that better explain observations and experimental results can replace old theories.

Explanation: Theories more than ten years old are usually out of date. Scientists want to prove that the work of other scientists is wrong. New evidence that supports a change prompts scientists to modify earlier theories.

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3. What is a manometer used to determine?

Gemiola [76]

Answer:

It's used to indicate pressure

3 0

2 years ago

Read 2 more answers

An airplane is moving at 350 km/hr. If a bomb is

Molodets [167]

Answers:

a) -171.402 m/s

b) 17.49 s

c) 1700.99 m

Explanation:

We can solve this problem with the following equations:

$y=y_{o}+V_{oy}t-\frac{1}{2}gt^{2}$ (1)

$x=V_{ox}t$ (2)

$V_{f}=V_{oy}-gt$ (3)

Where:

$y=0 m$ is the bomb's final jeight

$y_{o}=1.5 km \frac{1000 m}{1 km}=1500 m$ is the bomb'e initial height

$V_{oy}=0 m/s$ is the bomb's initial vertical velocity, since the airplane was moving horizontally

$t$ is the time

$g=9.8 m/s^{2}$ is the acceleration due gravity

$x$ is the bomb's range

$V_{ox}=350 \frac{km}{h} \frac{1000 m}{1 km} \frac{1 h}{3600 s}=97.22 m/s$ is the bomb's initial horizontal velocity

$V_{f}$ is the bomb's fina velocity

Knowing this, let's begin with the answers:

With the conditions given above, equation (1) is now written as:

$y_{o}=\frac{1}{2}gt^{2}$ (4)

Isolating $t$ :

$t=\sqrt{\frac{2 y_{o}}{g}}$ (5)

$t=\sqrt{\frac{2 (1500 m)}{9.8 m/s^{2}}}$ (6)

$t=17.49 s$ (7)

<h3>a) Final velocity</h3>

Since $V_{oy}=0 m/s$ , equation (3) is written as:

$V_{f}=-gt$ (8)

$V_{f}=-(97.22)(17.49 s)$ (9)

$V_{f}=-171.402 m/s$ (10) The negative sign ony indicates the direction is downwards

<h3>c) Range</h3>

Substituting (7) in (2):

$x=(97.22 m/s)(17.49 s)$ (11)

$x=1700.99 m$ (12)

5 0

2 years ago

If my cylinder of air lasts 60 minutes while I am at the surface breathing normally, assuming all else is the same, how long wil

AfilCa [17]

Answer:

Explanation:

Let the volume of air be V. at atmospheric pressure, that is 10⁵ Pa

At 20 m below surface pressure will be

atmospheric pressure + hdg

10⁵ + 20 x 9.8 x 1000 = 2.96 x 10⁵Pa

At this pressure volume V becomes V/ 2.96

This volume will last 1/2.96 times time that is 60/2.96 = 20.27 minutes.

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3 years ago

El ancho de la uña de su dedo meñique se acerca a una unidad metrica comun ¿cual?

BartSMP [9]

Answer:

I have no clue what's really going on I'm just here to get answer maybe I will just try to get an answer but I have no clue I'm sorry I am confused and dint really know what to do here.

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3 years ago

A race car traveling at 44m/s slows at a constant rate to a velocity of 22m/s over 11 seconds , how far does it move during this

krok68 [10]

Answer:

add 44m/s and 22m/s then multiply it by 11

Explanation:

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2 years ago