Calculate the gravitational force of 2 masses of 131 kg and 145 kg if they are 5.2 m apart.

What is the entropy of a closed system in which 28 distinguishable grains of sand are distributed among 1000 distinguishable equ

baherus [9]

Answer:

193.4 J/K

Explanation:

For a closed system, the entropy is given as the natural logarithm of microstates.

The number of particles ( grains of sand ) N = 28

The number of boxes ( compartments ) M = 1000

Entropy is the logarithm of number of microstates

$S=ln \psi$

But the number of microstates is given by

$\psi=M^{N} hence S=ln M^{N}=\ln (1000^{28})= \boxed{193.4 J/K}$

4 0

3 years ago

Problem #3: 3.6. A diode has wdo = 0.4 µm and φj = 0.85 V. (a) What reverse bias is required to triple the depletion-layer width

Alchen [17]

Answer:

a) 6.8 Volt

b) 1.21Цm

Explanation:

We are given from the question that

The zero -bias depletion layer width( $W_{do}$ ) is 0.4Цm

The built in voltage φj is 0.85V

Now to calculate the reverse voltage( $V_{R}$ ) that would be required to triple the depletion - layer width.

The depletion - layer width ( $W_{d}$ ) of the diode has the formula

$W_{d} = W_{do} \sqrt{1 + \frac{V_{R} }{Qj} }$

For three times of $W_{d}$ we have

$3W_{d} = W_{do} \sqrt{1 +\frac{V_{R} }{Qj} }$

=> $\frac{V_{R} }{Qj} = 3^{2} -1$

=> $V_{R} = 8Qj$

Substituting value of φj

We have

$V_{R} = 8(0.85V)$

= 6.8 V

The required bias voltage $V_{R}$ is 6.8 V

The solution for the b part of the question is uploaded on first image

7 0

3 years ago

Three charges, Q1, Q2, and Q3 are located in a straight line. The position of Q2 is 0.301 m to the right of Q1. Q3 is located 0.

Alexxx [7]

Answer and Explanation: A charge exerts a force over another charge even if they are very far apart. This force is called <u>Electrostatic</u> <u>Force</u>.

If the two charges have the same sign, e.g. both aare positive, the force between them is opposite. If they have opposite sign, the force is towards each other. In other words, for electrostatic force, equal charges repel and different charges attract.

So,

1. If Q2 and Q3 have opposite signs, it is TRUE force in Q2 will go the left;

2. If the 2 are negative, they have the same sign, so it's FALSE force is to the right;

Sentences 3 and 4 are also TRUE due to the reasons described above;

5. If the charges have opposite signs, it means force is towards each other, or, to the right, so the sentence is TRUE;

1. Force is directly proportional to charges in Coulomb [C] and inversely proportional to distance squared in [m]:

$F=\frac{k.q.Q}{r^{2}}$

where k is a constant that equals 9 x 10⁹ N.m²/C²

Calculating force between 1 and 2:

$F_{12}=\frac{9.10^{9}(1.9.10^{-6})(2.84.10^{-6})}{(0.301)^{2}}$

$F_{12}=536.02.10^{-3}$ N

Force between 2 and 3:

$F_{23}=\frac{9.10^{9}(2.84.10^{-6})(3.03.10^{-6})}{(0.169)^{2}}$

$F_{23}=2711.63.10^{-3}$ N

Total force is the net force. Since Q2 is negative and the others are positive, force of 2 related to 1 is to left and related to 3 is to the right. Therefore, total force is the difference between those two forces:

$F_{T}=2711.63.10^{-3}-536.02.10^{-3}$

$F_{T}=2175.61.10^{-3}$ N

The total force on Q2 is 2175.61 x 10⁻³ N

2. For net force to be 0, $F_{13}=F_{23}$ . Suppose distance from 1 to 3 is x, then from 2 to 3 is $x-0.301$

Calculating:

$\frac{k(1.90.10^{-6})(3.03.10^{-6})}{x^{2}}=\frac{k(2.84.10^{-6})(3.03.10^{-6})}{(x-0.301)^{2}}$

$\frac{5.757.10^{-12}}{x^{2}} =\frac{8.6052.10^{-12}}{x^{2}-0.602x+0.090601}$

$\frac{5.757.10^{-12}}{8.6052.10^{-12}}=\frac{x^{2}}{x^{2}-0.602x+0.090601}$

$x^{2}=0.67x^{2}-0.40x+0.061$

$0.33x^{2}+0.40x-0.061=0$

roots = 0.14 or -1.35

Solving quadratic equation gives 2 roots, but one of the roots is negative. As distance is a measure that cannot be negative, the solution is x = 0.14.

The distance of Q3 relative to Q1 is 0.14 m

4 0

3 years ago

Describe how charge is transferred from the ruler to the metal rod.

spin [16.1K]

When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.

3 0

3 years ago

Read 2 more answers

Right or left? Summer and Winter or day and night?

evablogger [386]

Answer:

The answer is left

Explanation:

Sorry if im worng

6 0

3 years ago

Read 2 more answers