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3 years ago

How could you record the number 4000 and report 2 significant figures?

Physics

1 answer:

yawa3891 [41]3 years ago

5 0

Explanation:

Write in scientific notation.

4000 = 4.0×10³

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Which statementsabout a neutral atom are correct? Check all that apply.

KIM [24]

Answer:

1, 2, 4, 5 are correct

Explanation:

1) This is true because In a neutral atom, the number of positive charges (protons) is equal to the number of negative charges (electrons).

2) This is true because the mass of the atom which is made up of the protons and neutrons, is located in the tiny nucleus.

3) This is not true because the positively charged particles in the nucleus are called protons.

4) This is true because electrons move around the nucleus in diffuse areas known as orbitals.

5) This is true because opposite charges attract each other. And electron is a negative charge.

6) This is not true because the radius of the electron cloud is normally 10,000 times larger than the radius of the nucleus.

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3 years ago

What current flows through a 2.54cm diameter rod of pure silicon that is 20cm long when 1000V is applied?

vfiekz [6]

Answer: $0.0039\ A$

Explanation:

Given

Diameter of the rod $d=2.54\ cm$

length of rod is $l=20\ cm$

Resistivity of silicon is $\rho=6.4\times 10^2\ \Omega-m$

cross-section of the rod $A$

$\Rightarrow A=\dfrac{\pi d^2}{4}\\\\\Rightarrow A=\dfrac{3.142\times 2.54^2\times 10^{-4}}{4}\\\\\Rightarrow A=5.067\times 10^{-4}\ m^2$

Resistance of rod is R

$\Rightarrow R=\dfrac{\rho l}{A}$

$\Rightarrow R=\dfrac{640\times 0.20}{5.067\times 10^{-4}}\\\\\Rightarrow R=25.26\times 10^4\ \Omega$

Current is given by

$\Rightarrow I=\dfrac{V}{R}\\\\\Rightarrow I=\dfrac{1000}{25.26\times 10^4}\\\\\Rightarrow I=0.0039\ A$

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2 years ago

How can energy conservation be considered an energy source?

Brut [27]

Answer:This could be in the form of using fewer energy services or using devices that require less energy.

Explanation:

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3 years ago

A simple pendulum consists of a mass M attached to a string oflength L andnegligible mass. For this system, when undergoing smal

PilotLPTM [1.2K]

The frequency of the pendulum is independent of the mass on the end. (c)

This means that it doesn't matter if you hang a piece of spaghetti or a school bus from the bottom end. If there is no air resistance, and no friction at the top end, and the string has no mass, then the time it takes the pendulum to swing from one side to the other only depends on the length of the string.

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3 years ago

A EXAMPLE OF WHEN BOTH PHYSICAL CHANGE AND CHEMICAL CHANGE OCCUR 3 EXAMPLES

kvasek [131]

Answer:

I know 1, that is in the case of a burning of a candle.

Explanation:

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3 years ago