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3 years ago

14

As an analogy to wave packets, consider an "automobile packet" that occurs near the scene of an accident on a freeway. The phase

speed is analogous to the speed of individual automobiles as they move through the backup caused by the accident. The group speed can be identified as the speed of the leading edge of the packet of cars. For the automobile packet, which of the following is true? a. The group speed is greater than the phase speed. b. The group speed is the same as the phase speed c. The group speed is less than the phase speed

1 answer:

Masteriza [31]3 years ago

7 0

Answer:

c. The group speed is less than the phase speed.

Explanation:

For an individual the speed is given by v phase = w/k

w is angular frequency and k is wave number.

This is called phase speed. Group speed is the speed of wave packet.The rate of advance of a crest on a single wave point which is fixed phase.

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Does specific heat of a substance depend on its temperature?

lara [203]

Answer:

temperature

Explanation:

In general, the specific heat also depends on the temperature. The table below lists representative values of specific heat for various substances. Except for gases, the temperature and volume dependence of the specific heat of most substances is weak.

4 0

2 years ago

Two insulated copper wires of similar overall diameter have very different interiors. One wire possesses a solid core of copper,

Marrrta [24]

Answer:

a

Solid Wire $I = 0.01237 \ A$

Stranded Wire $I_2 = 0.00978 \ A$

b

Solid Wire $R = 0.0149 \ \Omega$

Stranded Wire $R_1 = 0.0189 \ \Omega$

Explanation:

Considering the first question

From the question we are told that

The radius of the first wire is $r_1 = 1.53 mm = 0.0015 \ m$

The radius of each strand is $r_0 = 0.306 \ mm = 0.000306 \ m$

The current density in both wires is $J = 1750 \ A/m^2$

Considering the first wire

The cross-sectional area of the first wire is

$A = \pi r^2$

= > $A = 3.142 * (0.0015)^2$

= > $A = 7.0695 *10^{-6} \ m^2$

Generally the current in the first wire is

$I = J*A$

=> $I = 1750*7.0695 *10^{-6}$

=> $I = 0.01237 \ A$

Considering the second wire wire

The cross-sectional area of the second wire is

$A_1 = 19 * \pi r^2$

=> $A_1 = 19 *3.142 * (0.000306)^2$

=> $A_1 = 5.5899 *10^{-6} \ m^2$

Generally the current is

$I_2 = J * A_1$

=> $I_2 = 1750 * 5.5899 *10^{-6}$

=> $I_2 = 0.00978 \ A$

Considering question two

From the question we are told that

Resistivity is $\rho = 1.69* 10^{-8} \Omega \cdot m$

The length of each wire is $l = 6.25 \ m$

Generally the resistance of the first wire is mathematically represented as

$R = \frac{\rho * l }{A}$

=> $R = \frac{ 1.69* 10^{-8} * 6.25 }{ 7.0695 *10^{-6} }$

=> $R = 0.0149 \ \Omega$

Generally the resistance of the first wire is mathematically represented as

$R_1 = \frac{\rho * l }{A_1}$

=> $R_1 = \frac{ 1.69* 10^{-8} * 6.25 }{5.5899 *10^{-6} }$

=> $R_1 = 0.0189 \ \Omega$

3 0

3 years ago

Properties such as luster conductivity and flexibility are used to describe what type of elements

pickupchik [31]

Answer: metals.

Justification:

There are 118 elements which you can find in the periodic table ordered by atomic number. Those elements my be classified into metals, non-metals and metalloids.

The metals are placed on the left side of the periodic table. The metals share the properties of luster, conductivity and flexibility.

The properties of non-metals (which are on the right side of the periodic table) are opposite to those of metals: opaque, low conductivity and brittle.

Metalloids have in between properties.

Copper, for example is a metal: it has luster, is flexible and is highly conductive of the electricity (and temperature).

4 0

3 years ago

What provides the force that causes magma to erupt to the surface

olga2289 [7]

Geothermal energy provides force that causes magma to erupt to the surface

3 0

3 years ago

3. Neha travels 4 m towards the north, 3m towards the east, and then 7 m towards south, find the displacement and total distance

Digiron [165]

Answer:

Explanation:

Explanation: total displacement =3√2m. and total distance covered=14m. I hope this is right and helps u.

7 0

3 years ago