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IrinaVladis [17]

2 years ago

13

Water is formed when two hydrogen atoms bond to an oxygen atom. The hydrogen and the oxygen in this example are different A) com

plexes. B) compounds. C) elements. AND) mixtures.

2 answers:

Over [174]2 years ago

6 0

Answer:

it's not c, it's a, i did it on the usatextprep

Explanation:

Alik [6]2 years ago

5 0

C. Elements
elements are found in periodic table (in 1 box)

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A floating balloon can be formed when the substance helium is released from a compressed container into a flat rubber balloon. T

mel-nik [20]

Helium’s state when the decompressed helium atoms expand and float up, making the rubber balloon expand around them and float with them is gas.

<span>Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the elements.</span>

6 0

2 years ago

Read 2 more answers

A.Whale communication. Blue whales apparently communicate with each other using sound of frequency 17.0 Hz, which can be heard n

Y_Kistochka [10]

A. 90.1 m

The wavelength of a wave is given by:

$\lambda=\frac{v}{f}$

where

v is the speed of the wave

f is its frequency

For the sound emitted by the whale, v = 1531 m/s and f = 17.0 Hz, so the wavelength is

$\lambda=\frac{1531 m/s}{17.0 Hz}=90.1 m$

B. 102 kHz

We can re-arrange the same equation used previously to solve for the frequency, f:

$f=\frac{v}{\lambda}$

where for the dolphin:

v = 1531 m/s is the wave speed

$\lambda=1.50 cm=0.015 m$ is the wavelength

Substituting into the equation,

$f=\frac{1531 m/s}{0.015 m}=1.02 \cdot 10^5 Hz=102 kHz$

C. 13.6 m

Again, the wavelength is given by:

$\lambda=\frac{v}{f}$

where

v = 340 m/s is the speed of sound in air

f = 25.0 Hz is the frequency of the whistle

Substituting into the equation,

$\lambda=\frac{340 m/s}{25.0 Hz}=13.6 m$

D. 4.4-8.7 m

Using again the same formula, and using again the speed of sound in air (v=340 m/s), we have:

- Wavelength corresponding to the minimum frequency (f=39.0 Hz):

$\lambda=\frac{340 m/s}{39.0 Hz}=8.7 m$

- Wavelength corresponding to the maximum frequency (f=78.0 Hz):

$\lambda=\frac{340 m/s}{78.0 Hz}=4.4 m$

So the range of wavelength is 4.4-8.7 m.

E. 6.2 MHz

In order to have a sharp image, the wavelength of the ultrasound must be 1/4 of the size of the tumor, so

$\lambda=\frac{1}{4}(1.00 mm)=0.25 mm=2.5\cdot 10^{-4} m$

And since the speed of the sound wave is

v = 1550 m/s

The frequency will be

$f=\frac{v}{\lambda}=\frac{1550 m/s}{2.5\cdot 10^{-4} m}=6.2\cdot 10^6 Hz=6.2 MHz$

3 0

2 years ago

Although it shouldn’t have happened, on a dive i fail to watch my spg and run out of air. if my buddy is close by, my best optio

leva [86]

Answer:

B ) Ascend using my buddy alternative air source / make an emergency Ascent

Explanation:

From the description it can be seen his buddy is close by of which he can easily use the alternative air source. Also we can see that he is closer to the water surface than his buddy, of which controlled emergency swimming ascent is highly favourable in this condition.

5 0

2 years ago

Read 2 more answers

A balloon of mass M is floating motionless in the air. A person of mass less than M is on a rope ladder hanging from the balloon

Alex73 [517]

Answer:

Down with a speed less than v

Explanation:

Let the person's mass be represented by m

The mass of the balloon = M

Total momentum is conserved thus F = external force = 0

when the person starts to climb the ladder, external force is still equal to zero.

We know that change is p = F * change in t

in this equation, F is the external force = 0

Hence change in p = 0

This means that total momentum is conserved thus F = external force = 0

(owing to the fact that exterior forces on the system are balanced)

Since all external force was zero before they began to climb the ladder, as they climb all external forces will still = 0

Thus, As the person starts moving

mv + MV = 0

or mv = MV

V = mv/M

Since M > m, m/M will definitely be a number that is less than 1,

Hence, V = (a number less than 1)v.

This means that V < v, or the balloon moves down a speed V which is less than v.

4 0

2 years ago

Which biome contains mostly coniferous trees and receives 35 to 100 cm of rain per year?

a_sh-v [17]

The question is incomplete as it does not have the options which are:

deciduous forest

taiga (boreal forest)

temperate rainforest

tropical rainforest

Answer:

Taiga (boreal forest)

Explanation:

A Biome refers to the habitat which is occupied by flora and fauna living in similar conditions. These biomes are distinguished based on many features like precipitation, temperature and many other physical factors.

In the given question, the biome which receives an annual rainfall of 35 to 100 cm annually and is mostly covered by the coniferous trees is known as "Taiga biome" which is also known as Boreal forest.

The Taiga biome is one of the largest terrestrial biomes which is present in Eurasia and North America. The biome is characterised by the conifers trees and therefore is also known as the Coniferous trees.

Thus, Taiga (boreal forest) is the correct answer.

4 0

2 years ago