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3 years ago

Why-does-the-energy-of-a-sound-wave-decrease-over-time

1 answer:

7 0

The sound wave never actually loses energy, the bulk of energy it had at the beginning of the sound, is spread out into a sphere, making it decrease in amplitude and frequency.

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A balloon will stick to a wooden wall if the balloon is charged

grigory [225]

<h2>Answer: either way</h2>

The balloon contains neutral charge atoms, that is, it has the same number of electrons (negative charge), protons (positive charge) and neutrons (no charge).

Then, when two objects come into contact, the electrons of one of them can become part of the other.

Thus, by bringing the balloon closer to the wall, the wall, which is also made up of atoms, will reorder its charges in such a way that its electrons or protons become part of the balloon, charging it.

7 0

3 years ago

What is the wavelength of a wave that has a speed of 350 meters/second and a frequency of 140 hertz?

sergey [27]

Answer:2.5m

Explanation:

3 0

2 years ago

Radar use reflected microwaves to detect objects and measure their... what?

Sloan [31]

Height and depth..... for sure....

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4 years ago

Increasing the concentration of greenhouse gases in Earth's atmosphere decreases the transparency of the atmosphere to infrared

kondaur [170]

Answer:

Decreases the transparency of the atmosphere to infrared light.

Explanation:

When a large amount of green-house gases are present in the atmosphere, the layer of these gases become opaque to infrared radiation and radiation from the sun get trapped into these gases molecules. These excited molecules radiate this energy into our own atmosphere and that why the temperature of Earth is rising due to the Green-House effect.

8 0

3 years ago

True or false?

Ksju [112]

1. False

Explanation: it's exactly the opposite. In fact, Lenz's law states that the induced current and the induced emf in a conductor are generated in such a direction that opposes to the change in magnetic flux through the coil. This is summarized by the negative sign in the Faraday's Newmann Lenz law:

$\epsilon= -\frac{d\Phi }{dt}$

where $\epsilon$ is the emf induced and $\frac{d\Phi}{dt}$ is the rate of change of magnetic flux through the coil.

Lenz's law is a consequence of the law of conservation of energy. In fact, we have:

- If the magnetic flux through a coil is increasing, then the induced current has a direction such that the magnetic field generated by the coil is opposite to the direction of the external magnetic field, in order to decrease the total flux

- If the magnetic flux through a coil is decreasing, then the induced current has a direction such that the magnetic field generated by the coil is in the same direction as the external field, in order to increase the total flux

2. False

Explanation: the magnetic flux through a surface is given by

$\Phi = BA cos \theta$

where

B is the magnitude of the magnetic field

A is the surface area

$\theta$ is the angle between the direction of B and the normal vector to the surface

As we see, the magnetic flux depends not only on B and A, but also on the orientation of the coil with respect to the magnetic field.

3. False

Explanation:

- Sound waves are mechanical waves: mechanical waves are waves consisting of oscillations of the particles in a medium. Due to their nature, therefore, mechanical waves can propagate only in the presence of a medium

- Electromagnetic waves are NOT mechanical waves: they consist of oscillations of electric and magnetic fields, in a direction perpendicular to the direction of propagation of the wave. Since em waves are not mechanical waves, they do NOT need a medium to propagate, since they can also travel through a vacuum; therefore the original statement is false.

5 0

3 years ago