What causes an object to rotate

Do energy drinks actually provide energy?

denis-greek [22]

Answer:

Most energy drinks contain large amounts of caffeine, which can provide a temporary energy boost. Some energy drinks contain sugar and other substances. The boost is short-lived, however, and may be accompanied by other problems.

Explanation:

6 0

3 years ago

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A cube that is 20 nanometer on an edge contains 399,500 silicon atoms, and each silicon atom has 14 electrons and 14 protons. In

Sergeu [11.5K]

Answer:

Total 3 holes are available for conduction of current at 300K.

Explanation:

In order to develop a semiconductor, two type of impurities can be added as given below:

N-type Impurities: Pentavalent impurities e.g. Phosphorous, Arsenic are added to have an additional electron in the structure. Thus a pentavalent impurity creates 1 additional electron.
P-type Impurities: Trivalent impurities e.g. Boron, Aluminium are added to have a positive "hole" in the structure. Thus a trivalent impurity creates 1 hole.

Now for estimation of extra electrons in the impured structure is as

$N_{electrons-free}=n_{pentavalent \, atoms}\\N_{electrons-free}=4\\$

Now for estimation of "holes" in the impured structure is as

$N_{holes}=n_{trivalent \, atoms}\\N_{holes}=7\\$

Now when the free electrons and "holes" are available in the structure ,the "holes" will be filled by the free electrons therefore

$N_{holes-net}=N_{holes}-N_{electrons-free}\\N_{holes-net}=7-4\\N_{holes-net}=3$

So total 3 "holes" are available for conduction of current at 300K.

6 0

3 years ago

What is the mass of a dog running at a speed of 5 m/s and a momentum of 120.5 kgm/s?

viktelen [127]

Given:

Momentum of the dog (p) = 120.5 kg m/s

Speed of the dog (v) = 5 m/s

To Find:

Mass of the dog (m)

Concept/Theory:

$\underline{\underline{ \bf{\Large{Momentum}}}}$

It is defined as the quantity of motion contained in a body.
It is measured as the product of mass of the body and it's speed.
It is represented by p.
It's SI unit is kg m/s
Mathematical Representation/Equation of Momentum: $\boxed{ \bf{p = mv}}$

Answer:

By using equation of momentum, we get:

$\rm \longrightarrow m = \dfrac{p}{v} \\ \\ \rm \longrightarrow m = \dfrac{120.5}{5} \\ \\ \rm \longrightarrow m = 24.1 \: kg$

$\therefore$ Mass of the dog (m) = 24.1 kg

6 0

2 years ago

Which of the following best describes what causes the pases of the moon.?

Alborosie

The correct answer is<span> The earth casts a shadow on the moon

The Earth casts a shadow on the moon and that's why we can't see the remaining parts. The parts that we can see are what we call the lunar phases.</span>

4 0

3 years ago

Two plane mirrors are separated by 120°, as the drawing illustrates. If a ray strikes mirror M1 at a θ1 = 64° angle of incidence

tino4ka555 [31]

Angle, θ2 at which the light leaves mirror 2 is 56°

<u>Explanation:</u>

Given-

θ1 = 64°

So, α will also be 64°

According to the figure:

α + β = 90°

So,

β = 90° - α

= 90° - 64°

= 26°

β + γ + 120° = 180°

γ = 180° - 120° - β

γ = 180° - 120° - 26°

γ = 34°

γ + δ = 90°

δ = 90° - γ

δ = 90° - 34°

δ = 56°

According to the law of reflection,

angle of incidence = angle of reflection

θ2 = δ = 56°

Therefore, angle θ2 at which the light leaves mirror 2 is 56°

8 0

3 years ago