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3 years ago

11) We are past the year 1990: A.) Observation B.) Inference

Physics

2 answers:

Sliva [168]3 years ago

7 0

A an observation hehdhhdhdhdhdhhdhdhdhdhdb

Genrish500 [490]3 years ago

6 0

a would be the answer cuz u for sure know were passed 1990 u can see that its 2019

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The terminal velocity is not dependent on which one of the following properties? the drag coefficient 1 the force of gravity 2 c

ahrayia [7]

<h2>Answer: the falling time</h2>

Explanation:

When a body or object falls, basically two forces act on it:

1. The force of air friction, also called<em> </em><u><em>"drag force"</em></u> $D$ :

$D={C}_{d}\frac{\rho V^{2} }{2}A$ (1)

Where:

$C_ {d}$ is the drag coefficient

$\rho$ is the density of the fluid (air for example)

$V$ is the velocity

$A$ is the transversal area of the object

So, this force is proportional to the transversal area of the falling element and to the square of the velocity.

2. Its <u>weight </u>due to the gravity force $W$ :

$W=m.g$

(2)

Where:

$m$ is the mass of the object

$g$ is the acceleration due gravity

So, at the moment <u>when the drag force equals the gravity force, the object will have its terminal velocity:</u>

$D=W$ (3)

${C}_{d}\frac{\rho V^{2} }{2}A=m.g$ (4)

$V=\sqrt{\frac{2m.g}{\rho A{C}_{d}}}$ (5) This is the terminal velocity

As we can see, there is no "falling time" in this equation.

Therefore, the terminal velocity is not dependent on the falling time.

6 0

3 years ago

A long line of charge with uniform linear charge density λ1 is located on the x-axis and another long line of charge with unifor

Dahasolnce [82]

Answer:

A.The positive z-direction

Explanation:

We are given that

Linear charge density of long line which is located on the x-axis= $\lambda_1$

Linear charge density of another long line which is located on the y-axis= $\lambda_2$

We have to find the direction of electric field at z=a on the positive z-axis if $\lambda_1$ and $\lambda_2$ are positive.

The direction of electric field at z=a on the positive z-axis is positive z-direction .

Because $\lambda_1$ and $\lambda_2$ are positive and the electric field is applied away from the positive charge.

Hence, option A is true.

A.The positive z-direction

6 0

3 years ago

The current in a coil with a self-inductance of 1 mH is 2.8 A at t = 0, when the coil is shorted through a resistor. The total r

pogonyaev

Given:

L = 1 mH = $1\times 10^{-3}$ H

total Resistance, R = 11 $\Omega$

current at t = 0 s,

$I_{o}$ = 2.8 A

Formula used:

$I = I_{o}\times e^-{\frac{R}{L}t}$

Solution:

Using the given formula:

current after t = 0.5 ms = $0.5\times 10^{-3} s$

for the inductive circuit:

$I = 2.8\times e^-{\frac{11}{1\times 10^{-3}}\times 0.5\times 10^{-3}}$

$I = 2.8\times e^-5.5$

I =0.011 A

5 0

3 years ago

The denizens of a distant planet live under an atmosphere made predominantly of CO2 which is a dispersive medium while attending

LuckyWell [14K]

Since the frequency of sound in a medium is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.

<h3>What is a dispersive medium?</h3>

A dispersive medium is a medium which spreads out or disperses a substance passing through it.

Since CO2 is a dispersive medium, it means sound waves passing through it would be dispersed based on wavelength.

The note of a sound depends on its frequency, the higher the frequency, the higher the note.

Frequency of sound is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.

Learn more about dispersion of sound at: brainly.com/question/781734

5 0

2 years ago

The atoms in a solid move about freely

ivolga24 [154]

No, not exactly. They jiggle and tremble and vibrate a lot, but
they always basically stay in very nearly the same place.

It's like if you're allowed to go anywhere you want in your jail cell,
you wouldn't exactly call that "moving about freely".

6 0

3 years ago