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3 years ago

The desinty of a metal is 8.9g/cm3.what does it mean? what is the importance of this value?

Physics

2 answers:

prohojiy [21]3 years ago

6 0

Answer:

it means that the mass of 1 cm^3 of the metal is 8.9 grams.

The density is used to approximate how heavy and object is going to be. The mass of an object with known density and volume can be calculated using;

Mass = density × volume

Density is used to determine whether an object would float or sink in water of other substances.

Density is also considered in the selection of materials for construction, fabrications and manufacturing of products

Explanation:

Density is the measure of compactness of a substance. It is simply the mass of a unit volume of a substance.

Density = mass/volume

If the desinty of a metal is 8.9g/cm^3, it means that the mass of 1 cm^3 of the metal is 8.9 grams.

That means that the mass of a unit volume (1cm^3) of the metal is 8.9 g.

The density is used to approximate how heavy and object is going to be. The mass of an object with known density and volume can be calculated using;

Mass = density × volume

Density is used to determine whether an object would float or sink in water of other substances.

Density is also considered in the selection of materials for construction, fabrications and manufacturing of products

Komok [63]3 years ago

5 0

Answer:

It means that in every cubic centimeter volume of the metal, there is 8.9 grams mass of the metal.

Explanation:

It means that the degree of compaction of the atoms of the metal is 8.9 g/cm3.

It also means that in every cubic centimeter volume of the metal, there is 8.9 grams mass of the metal.

This information (density) will help us to understand how dense the the metal is, whether it will float or sink when immersed in a certain fluid.

Example, this metal will sink when it is immersed in water, because density of water is 1g/cm3, which is less than the density of the metal.

Also, this metal will float when immersed in a fluid like heavy crude oil, whose density is great than 8.9g/cm3.

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True false according to current atomic theory electrons are in fixed locations

Amanda [17]

That's false. According to current atomic theory and quantum mechanics, an electron is always PROBABLY SOMEWHERE in a fuzzy foggy area around the nucleus of the atom, and that's all we can ever say about it. There's no way to even TELL where the electron is, even if we had the technology to see things that small.

4 0

3 years ago

What is the likely identity of a metal if a sample has a mass of 63.5 g when measured in air and an apparent mass of 60.2 g when

Gre4nikov [31]

Answer:

Gold

Explanation:

Given:

Mass of sample = 63.5 g

Mass of water = 60.2 g

Find:

Object

Computation:

Mass of water displaced = 63.5 g - 60.2 g

Mass of water displaced = 3.3 g

So, volume in water = 3.3 cm³

Density = Mass / Volume

Density = 63.5 g / 3.3

Density = 19.24

So,

Object ,must be gold.

7 0

2 years ago

If an object is thrown in an upward direction from the top of a building 160 ft. High at an initial speed of 21.82 mi/h what is

viktelen [127]

To solve this problem we are going to use tow kinematic equations for falling objects.
1. Kinematic equation for final velocity: $V_{f}=V_{i}+gt$
where
$V_{f}$ is the final velocity
$V_{i}$ is the initial velocity
$g$ is the acceleration due to gravity $32 \frac{ft}{s^2}$
$t$ is the time
2. Kinematic equation for distance: $d=V_{i}t+ \frac{1}{2} gt^2$
where
$d$ is the distance
$V_{i}$ is the initial velocity
$V_{f}$ is the final velocity
$g$ is the acceleration due to gravity $32 \frac{ft}{s^2}$
$t$ is the time

First, we are going to convert 21.82 mi/h to ft/s:
$21.82 \frac{mi}{h} =31.21 \frac{ft}{s}$

Next, we are going to use the first equation to find how long it takes for the rock to reach its maximum height.
We know for our problem that the object is thrown in upward direction, so its velocity at its maximum height (before falling again) will be zero; therefore: $V_{f}=0$ . We also know that it initial speed is 31.21 ft/s, so $V_{i}=31.21$ . Lets replace those values in our formula to find $t$ :
$V_{f}=V_{i}+gt$
$0=31.21+(-32)t$
$-32t=-31.21$
$t= \frac{-31.21}{-32}$
$t=0.98$ seconds

Next, we are going to use that time in our second kinematic equation to find the distance the object reach at its maximum height:
$d=V_{i}t+ \frac{1}{2} gt^2$
$d=31.21(0.98)+ \frac{1}{2} (-32)(0.98)^2$
$d=15.22$ ft

Now we can add the height of the building and the maximum height of the object:
$d=160+15.22=175.22$ ft

Next, we are going to use that height (distance) in our second kinematic equation one more time to fin how long it takes for the object to fall from its maximum height to the ground:
$d=V_{i}t+ \frac{1}{2} gt^2$
$175.22=31.21t+ \frac{1}{2} (32)t^2$
$16t^2+31.21t-175.22=0$
$t=2.47$ or $t=-4.43$
Since time cannot be negative, $t=2.47$ is the time it takes the object to fall to the ground.

Finally, we can use that time in our first kinematic equation to find the final speed of the object when it hits the ground:
$V_{f}=V_{i}+gt$
$V_{f}=31.21+(32)(2.47)$
$V_{f}=110.25$ ft/s

We can conclude that the speed of the object when it hits the ground is 110.25 ft/s

5 0

3 years ago

(a) Neil A. Armstrong was the first person to walk on the moon. The distance between the earth and the moon is 3.85 108 m. Find

Goshia [24]

Answer:

It took 1.28 seconds to his voice to reach the Earth via radio waves.

Explanation:

The electromagnetic spectrum is the distribution of radiation due to the different frequencies at which it radiates and its different intensities, that radiation is formed by electromagnetic waves, which are transverse waves formed by an electric field and a magnetic field perpendicular to it.

The distribution of the radiation in the electromagnetic spectrum can also be given in wavelengths, but it is more frequent to work with it at frequencies, the highest being that of gamma rays, followed by X-rays, ultraviolet rays and the visible region , and those of lower frequencies, which correspond to infrared, microwave and radio waves.

Light propagates as electromagnetic wave in vacuum with a speed of $3x10^{8}m/s$ . Therefore, radio waves will have in vacuum the same speed.