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3 years ago

Why does a can collapse when a vacuum pump removes air from the can?

1 answer:

7 0

When a vacuum pump removes the air within the can, there is no more air molecules bombarding the inner surface of the can. Since the inner pressure=0, the atmospheric pressure will crush the can. Atmosoheric pressure is usually =1.3*10^5Pa.

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An electroscope is a simple device consisting of a metal ball that is attached by a conductor to two thin leaves of metal foil p

baherus [9]

Answer:

the electroscope separate by the presence of charge carriers

Explanation:

Metal bodies are characterized by having free (mobile) electrons. In the electroscope the plates are in balance; when the external metal ball is touched, a charge is introduced into the device, when the body that touched the ball is separated, an excess charge remains. This charge, being a metal, is distributed over the entire surface, giving a uniform density and an electric force of repulsion is created between the two charged sheets, which tends to separate the sheets. This force is counteracted by the tension component as the sheets are separated at a given angle, the separation reaches the point where

Fe - Tx = 0

Fe = Tx

In summary, the electroscope separate its leaves by the presence of charge carriers

3 0

3 years ago

A concert loudspeaker suspended high off the ground emits 34 W of sound power. A small microphone with a 1.0 cm2 area is 44 m fr

rjkz [21]

Answer:

I = 1.4 mW/m²

β = 91.46 dB

Explanation:

Sound intensity is the power per unit area of sound waves in a direction perpendicular to that area. Sound intensity is also called acoustic intensity.

For a spherical sound wave, the sound intensity is given by;

$I = \frac{P}{A}$

$I = \frac{P}{4\pi r^{2}}$

Where;

P is the source of power in watts (W)

I is the intensity of the sound in watt per square meter (W/m2)

r is the distance r away

Given:

P = 34 W,

A = 1.0 cm²

r = 44 m

The sound intensity at the position of the microphone is calculated to be;

$I = \frac{34}{4\pi (44)^{2}}$

I = 0.0013975 W/m²

≈ I = 0.0014 W/m² = 1.4 × 10⁻³ W/m²

I = 1.4 mW/m²

The sound intensity at the position of the microphone is 1.4 mW/m².

Sound intensity level or acoustic intensity level is the level of the intensity of a sound relative to a reference value. It is a a logarithmic quantity. It is denoted by β and expressed in nepers, bels, or decibels.

Sound intensity level is calculated as;

β $= 10log_{10}\frac{I}{I_{0}}$ dB

Where,

β is the Sound intensity level in decibels (dB)

I is the sound intensity;

I₀ is the reference sound intensity;

By pluging-in, I₀ is 1.0 × 10⁻¹² W/m²

∴ β $= 10log_{10}\frac{1.4 * 10^{-3} W/m^{2}}{1.0 * 10^{-12} W/m^{2}}$

β $= 10log_{10} (1.4 * 10^{9})$

β = 91.46 dB

The sound intensity level at the position of the microphone is 91.46 dB.

4 0

3 years ago

Need help please ASAP 39 points ???? 4 questions each have to be a paragraph the directions are there ?????

Hunter-Best [27]

Answer:

1) Magnetic resonance imaging (MRI) is a test that uses powerful magnets, radio waves, and a computer to make detailed pictures of the inside of your body.

Your doctor can use this test to diagnose you or to see how well you've responded to treatment. Unlike X-rays and computed tomography (CT) scans, MRIs don’t use the damaging ionizing radiation of X-rays.

2) MRIs employ powerful magnets which produce a strong magnetic field that forces protons in the body to align with that field. When a radiofrequency current is then pulsed through the patient, the protons are stimulated, and spin out of equilibrium, straining against the pull of the magnetic field.

3) Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from torn ligaments to tumors. MRIs are very useful for examining the brain and spinal cord.

4) The magnetic fields that change with time create loud knocking noises which may harm hearing if adequate ear protection is not used. They may also cause peripheral muscle or nerve stimulation that may feel like a twitching sensation. The radiofrequency energy used during the MRI scan could lead to heating of the body.

pls mark brainliest

4 0

2 years ago

An internal explosion breaks an object, initially at rest, into two pieces: A and B. Piece A has 1.9 times the mass of piece B.

Helen [10]

Kinetic energy of pieces A and B are 2724 Joule and 5176 Joule respectively.

<h3>What is the relation between the masses of A and B?</h3>

Let mass of piece A = Ma

Mass of piece B = Mb

Velocities of pieces A and B are Va and Vb respectively.
As per conservation of momentum,

Ma×Va = Mb×Vb

Here, Ma=1.9Mb

So, 1.9Mb × Va = Mb×Vb

=> 1.9Va = Vb

<h3>What are the kinetic energy of piece A and B?</h3>

Expression of kinetic energy of piece A = 1/2 × Ma × Va²
Kinetic energy of piece B = 1/2 × Mb × Vb²
Total kinetic energy= 7900J

=>1/2 × Ma × Va² + 1/2 × Mb × Vb² = 7900

=> 1/2 × Ma × Va² + 1/2 × (Ma/1.9) × (1.9Va)² = 7900

=> 1/2 × Ma × Va² ×(1+1.9) = 7900 j

=> 1/2 × Ma × Va² = 7900/2.9 = 2724 Joule

Kinetic energy of piece B = 7900 - 2724 = 5176 Joule

Thus, we can conclude that the kinetic energy of piece A and B are 2724 Joule and 5176 Joule respectively.

Learn more about the kinetic energy here:

brainly.com/question/25959744

#SPJ1

5 0

1 year ago

The candle burning

vodka [1.7K]

Answer:

Explanation:

its oxygen I hope i am correct have a great day.

3 0

2 years ago