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Andrei [34K]
3 years ago
9

Aquatic ecosystems consist of two different layers with respect to light. The photic zone is where light penetrates the water, a

t the surface and a little below. The aphotic zone is where the water is perpetually dark because the light cannot penetrate that deep into the water. The zone depths vary due to salinity and clarity of water.
Which of the following must be true about the organisms living in the aphotic zone?
A.
They have adapted to having no light for an energy source and are able to live in dark and cold areas.
B.
They all must move to the surface of the water once a day to receive adequate light energy.
C.
They have all become fluorescent so they can all be seen by one another.
D.
Many organisms have not been able to survive in the cold, dark waters, so population is low.
Physics
2 answers:
Lostsunrise [7]3 years ago
7 0

Answer: a

Explanation: it talks about how they live without that much light

Ivahew [28]3 years ago
4 0

Answer:

Answer A

Explanation:

Did the study island lesson

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Humans impact the Earth in good AND bad ways. <br><br>A) True <br><br>B) False
const2013 [10]

Answer:

True

Explanation:

yes we can see that we are helping animals but we create pollution which is very bad

7 0
3 years ago
What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor
const2013 [10]

Complete Question

An athlete at the gym holds a 3.0 kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg. Assume, a bit unrealistically, that the athlete's arm is uniform.

What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? Include the torque due to the steel ball, as well as the torque due to the arm's weight.

Answer:

The torque is  \tau = 34.3 \  N\cdot m

Explanation:

From the question we are told that

   The mass of the steel ball is  m  =  3.0 \  kg

    The length of arm is  l =  70 \ cm  = 0.7 \  m

    The mass of the arm is m_a  = 4.0 \  kg

Given that the arm of the athlete is uniform them the distance from the shoulder to the center of gravity of the arm is mathematically represented as

       r = \frac{l}{2}

=>    r = \frac{ 0.7}{2}  

=>    r = 0.35 \ m  

Generally the magnitude of torque about the athlete shoulder is mathematically represented as

      \tau =  m_a * g * r  + m * g *  L

=>    \tau =  4 * 9.8 * 0.35 + 3 * 9.8 *  0.70

=>    \tau = 34.3 \  N\cdot m

5 0
2 years ago
M (b) Calculate the speed of an electron that is accelerated through the same electric potential difference.
MaRussiya [10]

The speed of a electron that is accelerated from rest through an electric potential difference of 120 V  is 6.49\times10^6m/s

<h3>How to calculate the speed of the electron?</h3>

We know, that the  energy of the system is always conserved.

Using the Law of Conservation of energy,

\triangle K+\triangle U=0

Here, K is the kinetic energy and U is the potential energy.

Now, substituting the formula of U and K, we get:

(\frac{1}{2} mv^2)+(-q\triangle V) =0------(1)

Here,

m is the mass of the electron

v is the speed of the electron

q is the charge on the electron

V is the potential difference

Let v_f and v_i represent the final and initial speed.

Here, v_i =0

Solving for v_f, we get:

v_f=\sqrt{\frac{-2q\triangle V}{m} }

=\sqrt{\frac{2\times1.602\times10^{-19}\times 120}{9.109\times10^{-31}} }

=6.49\times10^6m/s

To learn more about the conservation of energy, refer to:

brainly.com/question/2137260

#SPJ4

4 0
1 year ago
What is pitch related to?
Jlenok [28]
Pitch is related to frequency
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3 years ago
Relative means
Bond [772]

Answer:As a noun relative means a person who is connected with others by blood.

7 0
2 years ago
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