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3 years ago

Why does the frequency of a siren get higher as an ambulance using that siren gets closer?

2 answers:

7 0

The answer is D. As the ambulance gets closer, the sound waves are compressed relative to the person; so the frequency increases.

yarga [219]3 years ago

7 0

I would say that the answer is D)

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How does energy change as it moves through the ecosystem?

Galina-37 [17]

Answer:

by the animeals and himens getting vood

Explanation:

3 0

3 years ago

Read 2 more answers

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a lar

horrorfan [7]

Answer:

W= 4.89 KJ

Explanation:

Lets take

temperature of hot water T₁ = 100⁰C

T₁ = 373 K

Temperature of cold ice T₂= 0⁰C

T₂ = 273 K

The latent heat of ice LH= 334 KJ

The heat rejected by the engine Q= m .LH

Q₂= 0.04 x 334

Q₂= 13.36 KJ

Heat gain by engine = Q₁

For Carnot engine

$Q_1=\dfrac{T_1}{T_2}Q_2$

$Q_1=\dfrac{373}{273}\times 13.36$

Q₁ = 18.25 KJ

The work W= Q₁ - Q₂

W= 18.25 - 13.36 KJ

W= 4.89 KJ

7 0

3 years ago

Read 2 more answers

What r photons? <br> ........................,........,..........

AVprozaik [17]

Answer:

in physics, a photon is a bundle of electromagnetic energy. It is the basic unit that makes up all light

Explanation:

6 0

3 years ago

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The rate constants for the reactions of atomic chlorine and of hydroxyl radical with ozone are given by 3 × 10-11 e-250/T and 2

Vlada [557]

Answer:

Calculate the ratio of the rates of ozone destruction by these catalysts at 20 km, given that at this altitude the average concentration of OH is about 100 times that of Cl and that the temperature is about -50 °C

Knowing

Rate constants for the reactions of atomic chlorine and of hydroxyl radical with ozone are given by 3x $10^{-11} e^{-255/T}$ and 2x $10^{-12} e^{-940/T}$

T = -50 °C = 223 K

The reaction rate will be given by [Cl] [O3] 3x $10^{-11} e^{-255/223} = 9.78^{-12} [Cl] [O3]$

Than, the reaction rate of OH with O3 is

Rate = [OH] [O3] 2x $10^{-12} e^{-940/223} = 2.95^{-14} [OH] [O3]$

Considering these 2 rates we can realize the ratio of the reaction with Cl to the reaction with OH is 330 * [Cl] / [OH]

Than, the concentration of OH is approximately 100 times of Cl, and the result will be that the reaction with Cl is 3.3 times faster than the reaction with OH

Calculate the rate constant for ozone destruction by chlorine under conditions in the Antarctic ozone hole, when the temperature is about -80 °C and the concentration of atomic chlorine increases by a factor of one hundred to about 4 × 105 molecules cm-3

Knowing

Rate constants for the reactions of atomic chlorine and of hydroxyl radical with ozone are given by 3x $10^{-11} e^{-255/T}$ and 2x $10^{-12} e^{-940/T}$

T = -80 °C = 193 K

The reaction rate will be given by [Cl] [O3] 3x $10^{-11} e^{-255/193} = 8.21^{-12} [Cl] [O3]$

Than, the reaction rate of OH with O3 is

Rate = [OH] [O3] 2x $10^{-12} e^{-940/193} = 1.53^{-14} [OH] [O3]$

Considering these 2 rates we can realize the ratio of the reaction with Cl to the reaction with OH is 535 * [Cl] / [OH]

Than, considering the concentration of Cl increases by a factor of 100 to about 4 × $10^{5}$ molecules $cm^{-3}$ , the result will be that the reaction with OH will be 535 + (100 to about 4 × $10^{5}$ molecules $cm^{-3}$ ) times faster than the reaction with Cl

Explanation:

4 0

3 years ago

What type of animals does Dr. Grant study?

Rasek [7]

Dr. Alan Grant is the main protagonist in Jurassic Park, with the book written primarily from his perspective. He is a paleontology professor at the University of Denver and receives research funding from the Hammond Foundation. He became a world-renowned paleontologist after discovering dinosaur nest fossils in Montana. Billionaire John Hammond chooses Dr. Grant to evaluate his dinosaur amusement park because of his professional expertise and unbiased opinion on dinosaurs.

Idk if this is related to what you ask but it might help.

7 0

3 years ago