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2 years ago

Your friend tells you that a shiny element has to be a metal. Do you agreed? Explain your reasoning

2 answers:

3 0

no i dont agree, because a glass bowl is shiny but its not a metal. just because some metals are shiny doesnt make all metals shiny

Mila [183]2 years ago

3 0

Yes because nonmetals are dull but metals are shiny.
Metals are luster and no metals are not.

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A NASA satellite has just observed an asteroid that is on a collision course with the Earth. The asteroid has an estimated mass,

Citrus2011 [14]

Answer:

v = 7934.2 m/s

Explanation:

Here the total energy of the Asteroid and the Earth system will remains conserved

So we will have

$-\frac{GMm}{r} + \frac{1}{2}mv_0^2 = -\frac{GMm}{R} + \frac{1}{2}mv^2$

now we know that

$v_0 = 660 m/s$

$M = 5.98 \times 10^{24} kg$

$m = 5 \times 10^9 kg$

$r = 4 \times 10^9 m$

$R = 6.37 \times 10^6 m$

now from above formula

$GMm(\frac{1}{R} - \frac{1}{r}) + \frac{1}{2}mv_0^2 = \frac{1}{2}mv^2$

now we have

$2GM(\frac{1}{R} - \frac{1}{r}) + v_0^2 = v^2$

now plug in all data

$2(6.67 \times 10^{-11})(5.98 \times 10^{24})(\frac{1}{6.37 \times 10^6} - \frac{1}{4 \times 10^9}) + (660)^2 = v^2$

$v = 7934.2 m/s$

5 0

2 years ago

You place an ice cube of mass 7.50×10−3kg and temperature 0.00∘C on top of a copper cube of mass 0.540 kg. All of the ice melts,

lbvjy [14]

Answer:

The value is $T_c = 12 .1 ^oC$

Explanation:

From the question we are told that

The mass of the ice cube is $m_i = 7.50 *10^{-3} \ kg$

The temperature of the ice cube is $T_i = 0^o C$

The mass of the copper cube is $m_c = 0.540 \ kg$

The final temperature of both substance is $T_f = 0^oC$

Generally form the law of thermal energy conservation,

The heat lost by the copper cube = heat gained by the ice cube

Generally the heat lost by the copper cube is mathematically represented as

$Q = m_c * c_c * [T_c - T_f ]$

The specific heat of copper is $c_c = 385J/kg \cdot ^oC$

Generally the heat gained by the ice cube is mathematically represented as

$Q_1 = m_i * L$

Here L is the latent heat of fusion of the ice with value $L = 3.34 * 10^{5} J/kg$

$Q_1 = 7.50 *10^{-3} * 3.34 * 10^{5}$

=> $Q_1 = 2505 \ J$

$2505 = 0.540 * 385 * [T_c - 0 ]$

=> $T_c = 12 .1 ^oC$

4 0

2 years ago

If a light ray from a candle strikes a mirror at an angle of 40° with the normal, at what angle will the ray reflect?

pav-90 [236]

Answer:

the correct answer is b: 25

8 0

2 years ago

Explain how this sand dune was created using the words weathering, erosion, and deposition.

MissTica

By abrasion, the sediment in the wind promotes erosion. The wind scatters sand, sand dunes created. When clay and silt are deposited by the wind. The presence of vegetation ground helps stop wind erosion.

<h3>What is an erosion ?</h3>

Earthen materials were worn away during erosion, a geological process in which they are moved by water or wind. Weathering, a related process that does not involve movement, dissolves and breaks down rock.

<h3>What is caused by erosion?</h3>

The process through which the Earth's surface ages is known as erosion. Natural forces like wind or glacier ice can create erosion. But when it comes to altering the Earth, nothing compares to a slow, constant movement of water, as anyone who has ever seen a picture of a Grand Canyon will attest.

To know more about Erosion visit:

brainly.com/question/3852201

#SPJ13

5 0

1 year ago

If an amount of heat Q is needed to increase the temperature of a solid metal sphere of diameter D from 4°C to 7°C, the amount o

Hitman42 [59]

Answer:

Q = c M ΔT where c is the heat capacity and M the mass present

Q2 / Q1 = M2 / M1 since the other factors are the same

M = ρ V where ρ is the density

M = ρ Π (d / 2)^2 where d is the diameter of the sphere

M2 / M1 = (2 D/2)^2 / (D/2)^2 = 4

It will take 4Q heat to heat the second sphere

7 0

1 year ago