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3 years ago

What happens in a chemical reaction?

Physics

1 answer:

Dimas [21]3 years ago

3 0

Answer:

d. Atoms are rearranged.

Explanation:

In a chemical reaction, what happens is that atoms are simply rearranged when the process takes place.

According to the law of conservation of mass "in a chemical reaction, matter is neither created nor destroyed but atoms are simply rearranged".

Therefore:

Atoms are not created
Atoms are not destroyed
Atoms are simply rearranged.

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A 97.3 kg horizontal circular platform rotates freely with no friction about its center at an initial angular velocity of 1.67 r

Yuliya22 [10]

Answer:

w = 1.14 rad / s

Explanation:

This is an angular momentum exercise. Let's define a system formed by the three bodies, the platform, the bananas and the monkey, in such a way that the torques during the collision have been internal and the angular momentum is preserved.

Initial instant. The platform alone

L₀ = I w₀

Final moment. When the bananas are on the shelf

we approximate the bananas as a point load and the distance is indicated

x = 0.45m

L_f = (m x² + I ) w₁

angular momentum is conserved

L₀ = L_f

I w₀ = (m x² + I) w₁

w₁ = $\frac{I}{m x^2 + I} \ w_o$

Let's repeat for the platform with the bananas and the monkey is the one that falls for x₂ = 1.73 m

initial instant. The platform and bananas alone

L₀ = I₁ w₁

I₁ = (m x² + I)

final instant. After the crash

L_f = I w

L_f = (I₁ + M x₂²) w

the moment is preserved

L₀ = L_f

(m x² + I) w₁ = ((m x² + I) + M x₂²) w

(m x² + I) w₁ = (I + m x² + M x₂²) w

we substitute

w = $\frac{m x^2 +I}{I + m x^2 + M x_2^2} \ \frac{I}{m x^2 + I} \ w_o$

w = $\frac{I}{I + m x^2 + M x_2^2} \ w_o$

the moment of inertia of a circular disk is

I = ½ m_p x₂²

we substitute

w = $\frac{ \frac{1}{2} m_p x_2^2 }{ \frac{1}{2} m_p x_2^2 + M x_2^2 + m x^2} \ \ w_o$

let's calculate

w = $\frac{ \frac{1}{2} \ 97.3 \ 1.73^2 }{ \frac{1}{2} \ 97.3 \ 1.73^2 + 21.9 \ 1.73^2 + 9.67 \ 0.45^2 } \ \ 1.67$

w = $\frac{145.60 }{145.60 \ + 65.54 \ + 1.958} \ \ 1.67$

w = 1.14 rad / s

5 0

3 years ago

The first astronomer to show that spiral nebulae (today called spiral galaxies) have large Doppler shifts was

solong [7]

William Parsons was the first astronomer to show that spiral nebulae have large Doppler shifts.

<h3>What are Spiral nebulae?</h3>

In space, a nebula is a huge cloud of gas and dust. Some nebulae, including multiple nebulae, are made of gas and dust that have been released from the explosion of a dead star called a supernova. There are other nebulae that are star-forming regions.
Edwin Hubble began observing Cepheid variables in many spiral nebulae, including the alleged Andromeda Nebula, in 1923, demonstrating that they are, in fact, full-fledged galaxies outside our own. Since then, the phrase spiral nebula has lost favor.
One group of astronomers believed that spiral nebulae were parts of our Milky Way galaxy, whereas the other group believed that these objects were actual galaxies that were outside of the Milky Way galaxy.

To learn more about Nebulae visit:

brainly.com/question/6452529

#SPJ4

8 0

2 years ago

"Stop to Think 16.1" on page 423 of your textbook. Also, for situation (a), descibe what happens to the speed of the wave, the f

garik1379 [7]

Answer:

wave speed= constant

frequency = increase

wavelength = decrease

Explanation:

Solution:

- The three basic parameters of a wave are speed, frequency and wavelength. These three parameters are related to each other by an expression:

v = f * λ

Where,

- v is the speed of the wave in m/s.

- f frequency of the wave in Hz.

- λ wavelength of the wave in m

- We are asked how would each of these parameter change if we move the hand up and down faster. The hand moves from a crest to trough faster than before and back again. We can see that the time between a cycle has decreased; hence, frequency f increases. Consequently, we can see that wave speed v remains constant - the medium of transfer of wave energy - remains same. Then from our relation above if we hold speed constant and increase f then the wavelength λ would have to decrease.

3 0

3 years ago

A mass weighing 4 lb stretches a spring 4in. Suppose the mass is given an additional in displacement downwards and then released

anastassius [24]

Answer:

4√6 rad/s

Explanation:

Since the spring is initially stretched a length of x = 4 in when the 4 lb mass is placed on it, since it is in equilibrium, the spring force, F = kx equals the weight of the mass W = mg.

So, W = F

mg = kx where m = mass = 4lb, g = acceleration due to gravity = 32 ft/s², k = spring constant and x = equilibrium displacement of spring = 4 in = 4 in × 1ft /12 in = 1/3 ft

making k the spring constant subject of the formula, we have

k = mg/x

substituting the values of the variables into the equation, we have

k = mg/x

k = 4 lb × 32 ft/s² ÷ 1/3 ft

k = 32 × 4 × 3

k = 384 lbft²/s²

Now, assuming there is no friction and no external force, we have an undamped system.

So, the natural frequency for an undamped system, ω = √(k/m) where k = spring constant = 384 lbft²/s² and m = mass = 4 lb

So, substituting the values of the variables into the equation, we have

ω = √(k/m)

ω = √(384 lbft²/s² ÷ 4 lb)

ω = √96

ω = √(16 × 6)

ω = √16 × √6

ω = 4√6 rad/s

5 0

3 years ago

Please help me (with explanation)

fiasKO [112]

Answer:

Answer is D.

Explanation:

When you're dealing with a plane mirror, the angle of incidence (angle of incoming ray to the normal) is equal to the angle of reflection (angle of the outgoing ray to the normal.

The only situation here where that is true is in option D (both angles are 40 degrees). In the other 3 answer options, one angle is 40 degrees and one angle is 50 degrees.

7 0

4 years ago

Read 2 more answers