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2 years ago

Currently, is our planet an open or closed system?

Physics

1 answer:

Dmitrij [34]2 years ago

8 0

Our planet is closed system because there is a limit of how much matter could be exchanged.

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A jet plane is cruising at 300 m/s when suddenly the pilot turns the engines up to full throttle. After traveling 4.0 km, the je

jenyasd209 [6]

<h2>The answer got is reasonable.</h2>

Explanation:

We have equation of motion v² = u² + 2as

Initial velocity, u = 300 m/s

Acceleration, a = ?

Final velocity, v = 400 m/s

Displacement,s = 4 km = 4000 m

Substituting

v² = u² + 2as

400² = 300² + 2 x a x 4000

a = 8.75 m/s² = 8.8 m/s²

The acceleration is 8.8 m/s²

The answer got is reasonable.

7 0

2 years ago

In the photoelectric effect, a photon with an energy of 5.3 × 10–19 J strikes an electron in a metal. Of this energy, 3.6 × 10–1

valentina_108 [34]

Answer:

The velocity of the photo electron is $6.11\times 10^5\ m/s$ .

Explanation:

Given that,

Supplied energy, $E_s=5.3\times 10^{-19}\ J$

Minimum energy of the electron to escape from the metal, $E_e=3.6\times 10^{-19}\ J$

We need to find the velocity of the photo electron. The energy supplied by the photon is equal to the sum of minimum escape energy and the kinetic energy of the escaping electron. So,

$5.3\times 10^{-19}\ J=3.6\times 10^{-19}\ J+K\\\\K=5.3\times 10^{-19}-3.6\times 10^{-19}\\\\K=1.7\times 10^{-19}\ J$

The formula of kinetic energy is given by :

$K=\dfrac{1}{2}mv^2\\\\v=\sqrt{\dfrac{2K}{m}} \\\\v=\sqrt{\dfrac{2\times 1.7\times 10^{-19}}{9.1\times 10^{-31}}} \\\\v=6.11\times 10^5\ m/s$

So, the velocity of the photo electron is $6.11\times 10^5\ m/s$ .

4 0

2 years ago

4. A metal fork has a density of 7.8 g/cm ³. Is this fork made up of aluminum?

Morgarella [4.7K]

No, aluminum has a density near 2.7 g/cm^3
<span>7.8 g/cm^3 is near the density of iron (or in the case of a fork, steel).
this is it

</span>

5 0

3 years ago

Which of the following pairs of elements is most likely to form an ionic bond?

ser-zykov [4K]

Answer: the answer is D. Aluminum and nitrogen

Explanation:

4 0

2 years ago

PLS HELP

RoseWind [281]

Answer:

A and C are correct.

4 0

2 years ago

Read 2 more answers