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2 years ago

Pls help i am in8th grade k12

Physics

1 answer:

omeli [17]2 years ago

6 0

Answer:

please i dont understand this

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In EXACTLY 13 words explain how global warming happens on Earth.

inysia [295]

By pollution rotting the air and making is worse for us to breath

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3 years ago

The first and second coils have the same length, and the third and fourth coils have the same length. They differ only in the cr

stealth61 [152]

Answer:

$\frac{R_2}{R_1}=\frac{A_1}{A_2}\\\frac{R_4}{R_3}=\frac{A_3}{A_4}$

Explanation:

The resistance of a conductor is directly proportional to its length and is inversely proportional to its cross-sectional area, this dependence is given by:

$R=\frac{\rho L}{A}$

$\rho$ is the material's resistance, L is the legth and A is the cross-sectional area.

For the first and second coils, we have:

$R_1=\frac{\rho L}{A_1}\\R_2=\frac{\rho L}{A_2}\\\rho L=R_1A_1\\\rho L=R_2A_2\\R_1A_1=R_2A_2\\\frac{R_2}{R_1}=\frac{A_1}{A_2}$

For the third and fourth coils, we have:

$R_3=\frac{\rho L'}{A_3}\\R_4=\frac{\rho L'}{A_4}\\\rho L'=R_3A_3\\\rho L'=R_4A_4\\R_3A_3=R_4A_4\\\frac{R_4}{R_3}=\frac{A_3}{A_4}$

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3 years ago

The sky is blue because: Select one: a. the index of refraction for air is slightly larger for blue than for red b. atomic hydro

lapo4ka [179]

Answer:

a. the index of refraction for air is slightly larger for blue than for red

5 0

2 years ago

Which of the following are true about S waves

shusha [124]

Answer:

3. they can travel through solids

4. they move rock at right angles to the direction of wave travel

Explanation:

S waves are called transverse waves they have the ability to move past the solids. They cannot move through the liquids, these waves are perpendicular to the direction of travel.

They are also called longitudinal waves, the ad is second to record on the seismograph as they slowly pass through the rocks. They have a speed of 3.4 to 7.2 km as per the boundary.

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2 years ago

An object is moving at a constant speed along a straight line. Which of the following statements is not true? A. There must be a

Svetradugi [14.3K]

Answer:

False statement = There must be a non-zero net force acting on the object.

Explanation:

An object is moving at a constant speed along a straight line. If the speed is constant then its velocity must be constant. We know that the rate of change of velocity is called acceleration of the object i.e.

$a=\dfrac{dv}{dt}$

a = 0

⇒ The acceleration of the object is zero.

The product of force and acceleration gives the magnitude of force acting on the object i.e.

F = m a = 0

⇒ The net force acting on the object must be zero.

So, the option (a) is not true. This is because the force acting on the object is zero. First option contradicts the fact.

6 0

3 years ago