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3 years ago

Which of the following is a chemical change?

1 answer:

3 0

a). Water is still H₂O after it freezes.

b). Ice is still H₂O after it melts.

c). Wire is still Cu when it's bent.

d). Paper combines with the O₂ in the air, and turns into
a lot of new compounds when it burns.

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Help me anybody please solve this

spin [16.1K]

Answer:

quizlet would help trust it really doess!!

4 0

3 years ago

Una esfera de radio 0.4m tiene una masa de 300kg, se desea sumergir en agua para saber si flota o no. En este ejercicio use la d

iragen [17]

Answer:

La esfera no flotará pero se hundirá cuando se coloque en el agua porque su densidad es mayor que la del agua.

Explanation:

De la pregunta anterior, se obtuvieron los siguientes datos:

Radio (r) de la esfera = 0,4 m

Masa de esfera = 300 Kg

Densidad del agua = 1000 Kg / m³

A continuación, determinaremos el volumen de la esfera. Esto se puede obtener de la siguiente manera:

Radio (r) de la esfera = 0,4 m

Pi (π) = 3,14

Volumen (V) de la esfera =?

V = 4/3 πr³

V = 4/3 × 3,14 × 0,4³

V = 12,56 / 3 × 0,064

V = 0,27 m³

A continuación, determinaremos la densidad de la esfera. Esto se puede obtener como se ilustra a continuación:

Masa de esfera = 300 Kg

Volumen de esfera = 0,27 m³

Densidad de esfera =?

Densidad = masa / volumen

Densidad de la esfera = 300 / 0,27

Densidad de la esfera = 1111,11 Kg / m³

Comparando la densidad del agua y la de la esfera.

Sustancia >>>>>>> Densidad

Agua >>>>>>>>>>> 1000 Kg / m³

Esfera >>>>>>>>>> 1111,11 Kg / m³

De la ilustración anterior, podemos ver que la densidad de la esfera es mayor que la del agua.

Por lo tanto, la esfera no flotará sino que se hundirá cuando se coloque en el agua porque su densidad es mayor que la del agua.

4 0

3 years ago

A sound wave with a waveenght of 2.5 meters traves 660 meters in 2 seconds calculate the frequemcy of the wave to cacuation the

finlep [7]

The frequency of the wave is 132 Hz

Explanation:

To calculate the speed of the wave, we can use the following formula:

$v = \frac{d}{t}$

where

d is the distance travelled by the wave

t is the time elapsed

For the sound wave in this problem, we have:

d = 660 m is the distance travelled

t = 2 s is the time interval considered

Substituting and solving for v, we find the speed of the sound wave:

$v=\frac{660}{2}=330 m/s$

Now we can calculate the frequency of the wave by using the wave equation:

$v=f\lambda$

where

v = 330 m/s is the speed of the wave

$\lambda=2.5 m$ is the wavelength

f is the frequency

Solving for f, we find:

$f=\frac{v}{\lambda}=\frac{330}{2.5}=132 Hz$

Learn more about wavelength and frequency:

brainly.com/question/5354733

brainly.com/question/9077368

#LearnwithBrainly

7 0

3 years ago

Attractions between oppositely charged regions of nearby molecules are called

Reptile [31]

Answer:van der Waals forces

Explanation:van der Waals forces are weak bond that occurs between oppositely charged molecules like in the case of a magnet

5 0

3 years ago

If the photon scatters in the backward direction, what is the magnitude of the linear momentum of the electron just after the co

Strike441 [17]

Momentum is a vector quantity, and is always conserved. Whenever a collision occurs between two objects, the objects behave under the principle of conservation of momentum. Therefore, if an object moves in the direction opposite to its original direction after a collision, then this indicates that the momentum of the colliding object was greater than the object under consideration.

8 0

3 years ago