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3 years ago

Stars are formed in which of the following?

Physics

1 answer:

MAXImum [283]3 years ago

6 0

Stars are formed in nebulas, interstellar clouds of dust and gas.

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Which excited electron has the lowest energy?

bearhunter [10]

Answer:

The lowest energy of electron is the ground state.

Explanation:

4 0

2 years ago

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Determine the ratio of the resistivity of pure water to silver?

shutvik [7]

Silver is a very good conductor, this means its resistivity is very low (from table, we can check the precise value, which is $\rho_s = 1.6 \cdot 10^{-8} \Omega m$ ).

Pure water, instead, is a very bad conductor, this means its resistivity is very high, of order of $k \Omega \cdot m$ ( $10^3 \Omega m$ ). Even without knowing the precise value of the pure water resistivity, we can estimate the ratio between the pure water resistivity and the silver resistivity by comparing the two orders of magnitude:
$r= \frac{10^3 \Omega m}{10^{-8} \Omega m} \sim 10^{11}$

Therefore, we can say that the correct answer is
$3 \cdot 10^{11} : 1$

3 0

3 years ago

Choose all of the true statements regarding the relationship between voltage, resistance, and current. Current is measured in am

AveGali [126]

-- Current is measured in amps. (You can use any symbol you want to represent current, but the most common one is " I ", not "Δ".)

-- The relationship between current, voltage, and resistance is mathematically defined by Ohm's Law.

-- Current is the flow of electrons through a circuit.

-- (Ohm's Law is NOT mathematically represented by the equation V=I/R.) It should be V = I · R .

(When solving for Resistance in a circuit and both voltage and current are known values, the equation I =V*R is not true, and not the way to solve it.) If the resistance is what you're looking for, then the equation to use is R = V / I .

-- If the voltage in a circuit is increased, the current will also increase.

6 0

3 years ago

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A speaker vibrates at a frequency of 200 hz what is its period

Norma-Jean [14]

Period = (1) / (frequency)

Period = (1) / (200 per second) = 0.005 second = 5 milliseconds

5 0

3 years ago

Read 2 more answers

The end diastolic volume of a heart is 140 mL Assume that it is a sphere. At end diastole, the intraventricular pressure is 7mmI

Vera_Pavlovna [14]

Answer:

Explanation:

We know that, V = 140 mL = 0.00014 m3

Assume that it is a sphere. so, we have

V = (4/3) \pir3

r3 = (0.00014 m3) (3) / (4) (3.14)

r = \sqrt[3]{}\sqrt[3]{}3\sqrt{}3.34 x 10-5 m3

r = 1.93 x 10-7 m

(a) The wall tension at end diastole will be given as :

using a formula, we have

T = P r / 2 H

where, P = intraventricular pressure at end diastole = 7 mmHg = 933.2 Pa

H = wall thickness at this time = 0.011 m

then, we get

T = (933.2 Pa) (1.93 x 10-7 m) / 2 (0.011 m)

T = 8.18 x 10-3 N

(b) The wall tension at the end of isovolumetric contraction will be given as :

using a formula, we have

T = P r / 2 H

where, P = intraventricular pressure at end of isovolumetric contraction = 80 mmHg = 10665.7 Pa

H = wall thickness at this time = 0.011 m

then, we get

T = (10665.7 Pa) (1.93 x 10-7 m) / 2 (0.011 m)

T = 9.35 x 10-2 N

(d) The wall stress from A and B which will be given as :

we know that, \sigma = T / w

For part A, we have

\sigmaA = (8.18 x 10-3 N) / (0.011 m)

\sigmaA = 0.743 N/m

For part B, we have

\sigmaB = (9.35 x 10-2 N) / (0.011 m)

\sigmaB = 8.5 N/m

4 0

2 years ago