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3 years ago

Since prehistoric times what has been the correlation between atmospheric carbon dioxide level and global temperature

Physics

1 answer:

kondaur [170]3 years ago

6 0

Answer:

The correlation based on one source of estimates of temperatures and CO2 levels (namely the Vostok data) is <em>positive</em> with an R^2 coefficient of about 0.75.

Explanation

There are only few sources of data for us to estimate this correlation over long periods of time. One of these are the "Vostok" ice core data that span some 400 thousand years of estimated temperature and CO2 levels (https://cdiac.ess-dive.lbl.gov/trends/co2/vostok.html). A paper referenced below shows the coefficient of determination of 0.75.

It should be pointed out that a correlation, and even more so causality between historical CO2 and temperatures has been subject of an ongoing scientific debate. This debate is further compounded by politically motivated factors. So it remains to be added: use care adopting conclusions of others in this active field of science, try to perform own analysis of raw/original sources yourself, whenever possible.

Reference: https://www.researchgate.net/publication/23226792_Global_warming_and_carbon_Dioxide_through_sciences

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The volume flow rate of blood leaving the heart to circulate throughout the body is about 5 L/min for a person at rest. All this

skelet666 [1.2K]

Answer:

$n=2.9\times 10^9$

$A=1.88\times 10^{-8}\ m^2$

Explanation:

Given that

Q= 5 L/min

1 L = 10⁻³ m³/s

1 min = 60 s

Q=0.083 x 10⁻³ m³/s

d= 6 μm

v= 1 mm/s

So the discharge flow through one tube

q = A v

$A=\dfrac{\pi}{4}d^2$

$A=\dfrac{\pi}{4}\times (6\times 10^{-6})^2\ m^2$

A=2.8 x 10⁻¹¹ m²

v= 1 x 10⁻³ m/s

q= 2.8 x 10⁻¹⁴ m³/s

Lets take total number of tube is n

Q= n q

n=Q/q

$n=\dfrac{0.083\times 10^{-3} }{ 2.8\times 10^{-14}}$

$n=2.9\times 10^9$

Surface area A

A= π d L

$A=\pi \times 6\times 10^{-6}\times 10^{-3}\ m^2$

$A=1.88\times 10^{-8}\ m^2$

7 0

2 years ago

How do the individual forces compare when the rider experiences a sensation being lighter than his normal weight ? What is the a

shusha [124]

Answer:

When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.

Explanation:

A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.

Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.

When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma

When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma

However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg

When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0

6 0

2 years ago

3. A certain horizontal east-west lined wire has a mass of 0.2kg per meter of length and carries a current I. Impressed on the w

erica [24]

Answer:

i = 4.9 A

Explanation:

The expression for the magnetic force in a wire carrying a current is

F = i L x B

bold letters indicate vectors.

The direction of the cable is towards the East, the direction of the magnetic field is towards the North, so the vector product is in the vertical direction (z-axis) upwards and the weight of the cable is vertical downwards. Let's apply the equilibrium condition

F - W = 0

i L B = m g

They indicate the linear density of the cable λ = 0.2 kg / m

λ = m / L

m = λ L

we substitute

i B = λ g

i = $\frac{ \lambda \ g}{B}$

let's calculate

i = 0.2 9.8 / 0.4

i = 4.9 A

3 0

2 years ago

A student throws a water balloon vertically downward from the top of a building. The balloon leaves the thrower's hand with a sp

dusya [7]

from the question you can see that some detail is missing, using search engines i was able to get a similar question on "https://www.slader.com/discussion/question/a-student-throws-a-water-balloon-vertically-downward-from-the-top-of-a-building-the-balloon-leaves-t/"

here is the question : A student throws a water balloon vertically downward from the top of a building. The balloon leaves the thrower's hand with a speed of 60.0m/s. Air resistance may be ignored,so the water balloon is in free fall after it leaves the throwers hand. a) What is its speed after falling for 2.00s? b) How far does it fall in 2.00s? c) What is the magnitude of its velocity after falling 10.0m?

Answer:

(A) 26 m/s

(B) 32.4 m

(C) v = 15.4 m/s

Explanation:

initial speed (u) = 6.4 m/s

acceleration due to gravity (a) = 9.9 m/s^[2}

time (t) = 2 s

(A) What is its speed after falling for 2.00s?

from the equation of motion v = u + at we can get the speed

v = 6.4 + (9.8 x 2) = 26 m/s

(B) How far does it fall in 2.00s?

from the equation of motion $s=ut+0.5at^{2}$ we can get the distance covered

s = (6.4 x 2) + (0.5 x 9.8 x 2 x 2)

s = 12.8 + 19.6 = 32.4 m

c) What is the magnitude of its velocity after falling 10.0m?

from the equation of motion below we can get the velocity

$v^{2} = u^{2} + 2as\\v^{2} = 6.4^{2} + (2x9.8x10)\\V^{2} = 236.96\\v = \sqrt{236.96}$

v = 15.4 m/s

7 0

3 years ago

Identify the amplitude in the wave image below.*<br> F. G H J

alina1380 [7]

Answer:F
................

6 0

2 years ago