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3 years ago

Please Help Quick!!

1 answer:

7 0

The International Date Line (IDL) is a line that separates the world into two hemispheres. It was first established in 1884 during the International Meridian Conference which was attended by 26 countries. It is located at the 180° longitude, which is the east of Greenwich, United Kingdom.

The International Date Line does not follow a straight line because it has to avoid countries or groups of islands. The main purpose of the zigzag pattern of the IDL is to avoid confusion regarding time.

The IDL is important because it's the basis for our time zones. Back in the nineteenth century, scientists as well other professionals in various industries proposed to adopt the 24 time zone system which centered on the IDL's principle of adopting the proper "time". The IDL divides the world into two dates: the East of the IDL is a day behind compared to the West of the IDL.

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what are three examples of professions that use geographic skills, and how do those professions use those skills?

Effectus [21]

Environmental Consultant- you would have awareness of legislation and would know about collecting data and field surveys.

School Teacher- you could go on to teach geography at a secondary school.

Town Planner- can understand the different things that can effect towns, for example you would know what defenses to put in place.

4 0

3 years ago

Read 2 more answers

Imagine that you have obtained spectra for several galaxies and have measured the observed wavelength of a hydrogen emission lin

Lerok [7]

Answer:

A. z (galaxy 1) = -0.00515, z (galaxy 2) = -0.01707, z (galaxy 3) = -0.04008

B. v (galaxy 1) = -0.00517c, v (galaxy 2) = -0.01707c, v (galaxy 3) = -0.0401c

C. d (galaxy 1) = -21 Mpc,d (galaxy 2) = -69.4 Mpc, d (galaxy 3) = -163 Mpc

Explanation:

We begin by listing out the parameters we were given:

λ (obsv) = 656.3 nm, λ (emit 1) = 659.7 nm, λ (emit 2) = 667.7 nm,

λ (emit 3) = 683.7 nm

A) Using the Redshift formula, we have:

z = [λ (obsv) - λ (emit)] ÷ λ (emit)

For galaxy 1:

z = [λ (obsv) - λ (emit 1)] ÷ λ (emit 1)

z = (656.3 - 659.7) ÷ 659.7 = -0.00515

z = -0.00515

For galaxy 2:

z = [λ (obsv) - λ (emit 2)] ÷ λ (emit 2)

z = (656.3 - 667.7) ÷ 667.7 = -0.01707

z = -0.01707

For galaxy 3:

z = [λ (obsv) - λ (emit 3)] ÷ λ (emit 3)

z = (656.3 - 683.7) ÷ 683.7 = -0.04008

z = -0.04008

B) Using the Doppler formula, we have:

(Δλ ÷ λ) = v ÷ c

v = c * (Δλ ÷ λ)

but, z = (Δλ ÷ λ)

⇒ v = c * z

speed of light (c) = 3 x $10^{8}$ m/s

For galaxy 1:

v = c * z

Substitute z into the equation calculated from A) above

v = 3 x $10^{8}$ * (-0.00515)

v = -1.55 x $10^{6}$ m/s

v = -0.00517c

For galaxy 2:

v = c * z

Substitute z into the equation calculated from A) above

v = 3 x $10^{8}$ * (-0.01707)

v = -5.12 x $10^{6}$ m/s

v = -0.01707c

For galaxy 3:

v = c * z

Substitute z into the equation calculated from A) above

v = 3 x $10^{8}$ * (-0.04008)

v = -12.03 x $10^{6}$ m/s

v = -0.0401c

N.B: the negative value of velocity connotes that the galaxies are moving away from us (not towards us)

C) Using Hubbleʹs law, we have:

v = H · d

where:

v = velocity of a galaxy (km/s), d = distance (Mpc),

H = Hubble's constant (km/s/Mpc) = 73.8 km/sec

d = v ÷ H

We use the velocities calculated in B) above

For galaxy 1:

v = -1.55 x $10^{3}$ km/s

d = -1.55 x $10^{3}$ ÷ 73.8

d = -21 Mpc

For galaxy 2:

v = -5.12 x $10^{3}$ km/s

d = -5.12 x $10^{3}$ ÷ 73.8

d = -69.4 Mpc

For galaxy 3:

v = -12.03 x $10^{3}$ km/s

d = -12.03 x $10^{3}$ ÷ 73.8

d = -163 Mpc

N.B: distance cannot be a negative value

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3 years ago

Any land smaller than a continent surrounded by water

BARSIC [14]

Assuming you asked a question, a land form smaller than a continent surrounded by water would be an island.

3 0

3 years ago

When World War l began , the official United States policy was: A to enter on the side of the Allied Powers. B to enter on the s

Marina86 [1]

The USA generally tried to remain neutral during the beginning of world War 1. therefore, i think the correct answer would be C, to remain military and politically neutral. hope this helps you

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3 years ago

What type of unemployment is the result of a downturn in the economy and usually isn't permanent

Keith_Richards [23]

The answer is Cyclical unemployment.

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3 years ago