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3 years ago

What are the 7 continents?

Geography

1 answer:

krek1111 [17]3 years ago

4 0

Africa... antartica.. asia.. austrailia.. europe.. north america... south america.. those are the 7 continents

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Which country best illustrates Sustainable Development?

mote1985 [20]

Answer:

yes

Explanation:

because yes

4 0

3 years ago

Review<br> 1. Describe how plates create mountain ranges like the Himalayas.<br><br> Plzzz help ASAP

dexar [7]

Answer:

when the plates smash into eachother they start to move upward to create mountains. Mountain ranges can just be a large collection of plates that squished together.

7 0

3 years ago

A 215 kg rocket moving radially outward from Earth has a speed of 6.42 km/s when its engine shuts off 307 km above Earth's surfa

Vinvika [58]

<h2>GIVEN DATA</h2>

Mass of Rocket = m = 215 kg

Mass of Earth = M = $5.97*10^{24}$ kg

Radius of Earth = R = $6.37*10^6$ m

Gravitational Constant = G = $6.67*10^-11 \;\;m^3kg^{-1}s^{-2}$

Speed of Rocket = 6.42 km/s

Initial Height of Rocket from Earth's Surface = 307 km = $3.07*10^5$ m

Final Height of Rocket from Earth's Surface = 731 km = $7.31*10^5$ m

Initial Height from Earth's Centre = $R_i$ = $3.07*10^5 + 6.37*10^6 = 6.677*10^6$ m

Final Height from Earth's Surface = $R_f$ = $7.31*10^5 + 6.37*10^6 = 7.101*10^6$ m

(a) Kinetic Energy at Final Height = $K.E_f$

(b) Maximum Height of Rocket above Earth's Surface = $H_{max}$

<h2>EXPLANATION</h2>

Part (a):

As drag air is negligible, energy will be conserved.

$\therefore$ ΔE = 0

$K.E_i + U_i = K.E_f + U_f$

$K.E_f = U_f - K.E_i - U_i$

where, U is the potential energy of the system.

$K.E_f=\;G\frac{mM}{R_f} + \frac{1}{2}mv_i^2\;-\;G\frac{mM}{R_i}\;\;\;\;----------\;(1)$

Substituting Values and simplifying,

$K.E_f = 3.665*10^9 J$

Part (b):

The rocket will come to rest after reaching the maximum height. Therefore, its final velocity and consequently final kinetic energy will be zero.

$i.e.\;\;v_f = 0\;\;\;\&\;\;\; K.E_f=0$

Equation (1) will become,

$0\;=\;\;G\frac{mM}{R_f} + \frac{1}{2}mv_i^2\;-\;G\frac{mM}{R_i}$

$or\;\;\frac{1}{2}v_i^2= GM(\frac{1}{R_i}-\frac{1}{R_f})\\\\\frac{1}{2GM}v_i^2= (\frac{1}{R_i}-\frac{1}{R_f})\\\\\therefore\; R_f = \frac{2GMR_i}{2GM-v_i^2R_i}$

Substituting values and simplifying,

$R_f = 10.20*10^6 m$

which is the distance from the Earth's centre. To find the height of rocket from Earth's surface, we simply subtract the Earth's radius from above result.

$H_{max} = R_f - R$

$H_{max} = 10.20*10^6\;-\;6.37*10^6\\\\H_{max} = 3.83*10^6\;\;m$

4 0

3 years ago

The distance-size ratio for the Sun-Nearest other Star system is of an order of magnitude of

grandymaker [24]

Answer:

<u>Proxima Centauri is the closest star to that of the sun and being 4.22 light years away from the earth having an apparent magnitude of 12.95</u>.

Explanation:

Being a small and low mass star locate away from the sun in southern constellation being discovered in 1915 by Robert innings. Having an apparent magnitude of 11.3 having an Astronomical number of 12,950 from the orbital period of 550,000 years.

Proxima Centauri is a red dwarf star with a mass of eight times that of sun, and an average density that of sun, more than 85%of the radiation is infrared and has the regular activity of starspots.

Being closes to the sun around 32,000 years away. It thass an orbital period of 3.6 to 14 days.

6 0

3 years ago

What natural resource has played the largest role in the economies of the Persian gulf countries

lara [203]

Answer:

Oil

Explanation:

In 2002, the Persian Gulf nations of Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the UAE produced about 25% of the world's oil, held nearly two-thirds of the world's crude oil reserves, and about 35% of the world's natural gas reserves.

3 0

3 years ago

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