Physics Assignment Help: 30-kg hanging object is connected by a light..

Q) 30-kg hanging object is connected by a light, inextensible cord over a light, frictionless pulley to a 5.00-kg block that is sliding on a flat table. Taking the coefficient of kinetic friction as 0.162, find the tension in the string.

Sol:

It’s given that M1=5kg, M2=30kg, Also M1 is moving with acceleration a, caused by the Tension in string: T_s, and the friction, F_r, Hence aM1= T_s - uM1g, where u= coefficient of kinetic friction.

Similarly, the mass 30kg is moving with the same above acceleration a by the forces of weight and the Tension in the string,

Hence aM2=M2g- T_s

By adding the above two equations we get,

a= (M2g-uM1g)/ (M1+M2)

Therefore the tension in the string is given by,

T_s = M1g (M2-uM1)/ (M1+M2) +uM1g

By substituting the values in the above equation, we get

T_s = [5*9.8*(30-0.162*5)/ (5+30)] +0.162*5*9.8

  = 48.8N

Computer Science Assignment Help: Consensus algorithm

“Consensus algorithm”:  A group of ten people need to decide which one flavor of ice cream they will all order, out of three options. The algorithm can question and re-question the participants, and present the answers to the participants, until a consensus is reached. This exercise is somewhat more open-ended. Add your assumptions if necessary. Obviously, this algorithm might never result in an answer. Deal with that too.

Answer:

Step1: Please ask the group of people to select one flavor of ice cream and go to step 2.

Step2: Please plan for ordering the selected flavor and go to step 3 else go to step 1.

Step3: Please confirm from all the ten people whether they are ok with the selected flavor of ice cream, if yes go to step 4, else go to step 1.

Step4: Please go for the second round of confirmation from each one of them among the 10, if they are ok then go to step 5, else go to step 1.

Step5: Please order the selected flavor of ice-cream as a group of 10, if there is no discrepancy in the choice and go to step 6, else again go to step 1

Step6: Please wait for the waiter to serve the ice cream, if yes go to step 7, else go to step 8.

Step7: Enjoy having the delicious flavor of ice-cream, go to step 9.

Step8: Please remind the waiter again, and go to step 9.

Step9: Come out of the ice-cream shop as a group of 10 once you finish having it, else go to step 7.

Explanation:

Here we will not consider the percentage of members in a group opting for a flavor choice; instead we go for probability considering three to four members at a time. Hence we give three chances for the group of 10 members to select their choice, we are not ordering at the first choice we are giving two more other chances to choose so that as per the probability, at least after the third round for asking for the choice they all group of ten will come to the conclusion and they must be able to order it at that stage or else this keeps repeating until they all come to the conclusion.

Networking Homework Help: Explain why security is important for WLANs, even more ...

Q)Explain why security is important for WLANs, even more so than for wired networks. 

Sol:

More security is needed and security is very much important in case of wireless LANs, when compared to wired LANs. The main reason behind this is in case of wireless LANs by making use of the wireless authentication of the authorized wireless user any one can make use of it also hacking the wireless network is very easy if it is not password protected. Since in most of the WLANs the users are not protected by a unique password, since wireless LANs are always used in case of places like college campus or office campus where multiple users can access the network. Hence in case of wired LAN there is a need for the dedicated channel or cable through which every user can get connected to the network whereas in case of wireless LANs there is no need for it, sometimes it will not even ask for any security passwords. Hence any user can get connected to the network and use it without paying for it. As a result more security is important for WLAN’s when compared to Wired LAN.

Networking Assignment Help: What specific steps can be taken to improve security in WLANs...

Q)What specific steps can be taken to improve security in WLANs?

Sol:

 The below steps can be taken to improve the security in WLANs:

a) Initially wireless network has to be authorized and authenticated.

b) Also all the users try to get connected to that particular has to be authorized and authenticated.

c) Every user connected to the network has to be uniquely identified by their own unique username and password.

d) Multiple users with same username and password should not be allowed to connect to the network.

e) Every user has to be properly disconnected so that no one in queue must be able to continue to get connected to the network with their username and password.

Networking Homework Help: There is an ever growing range of physical media being offered such as fiber...

Q)There is an ever growing range of physical media being offered such as fiber, coax, satellite, IP over power lines, a number of wireless technologies, and more. Recently, the telephone companies announced 4G wireless communications and the IEEE has WiMax at Gigabit rates. What criteria would you use to select technologies for your business and for your home?

Sol:

The following are the criteria being used to select technologies for my business:

a) Multiple connections with maximum speed.

b) Higher bandwidth with lesser price.

c) Unlimited downloads with no additional charges.

d) Unlimited access within the coverage area irrespective of the machines being used.

e) Full time high speed networks without any congestion.

The following are the criteria being used to select technologies for my home:

a) Not more than two connections at a time.

b) Very lesser cost, irrespective of download limits.

c) Limited access but reduction in the monthly bill.

d) Moderate speed and bandwidth, irrespective of the congestion.

e) Lesser monthly rentals provided there are additional charges for download if it crosses the available limit.

Read and Answer: The International Centre for Radio Astronomy Research...

1) The International Centre for Radio Astronomy Research

Sol:

The International Centre for Radio Astronomy Research is a collaborative centre placed in Perth, Western Australia. They are already achieving research excellence in both astronomical science and engineering. The International Centre for Radio Astronomy Research has grown steadily from its launch in September 2009. An equal joint venture between The University of Western Australia and Curtin University, International Centre for Radio Astronomy Research has strong support from the West Australian as well as Australian governments and is working very closely with industry and research partners in Australia and in the entire world. Wireless internet (WIFI) inventor honored Curtin University has been recognized as Dr John O’Sullivan’s ground breaking work in astronomy and wireless technologies by bestowing John with an Honorary Science Doctorate. The latest telescope puts focus on high school discoveries where a new internet telescope was launched by State Education Minister Dr Elizabeth Constable at The Western University of Australia. Also
Sky Noise and Sensitivity Studies of Array Configurations and Antenna Elements were done for the Low-Frequency Band of the SKA.

Questions:

a) What is WIFI?

b) Expand ICRAR?

c) Internet telescope was launched by whom?

d) Who invented wireless internet?

Sol:

a) Wireless internet/wireless LAN.

b) International Centre for Radio Astronomy Research.

c) Dr. Elizabeth.

d) Dr John O’Sullivan

The total number of partitions of a k-element...

Q) The total number of partitions of a k-element
   set is denoted by B (k) and is called the k-th Bell number.

    Thus B (1) = 1and B (2) = 2.
   Need to find B (k) for k = 4, 5, 6.

Sol:

We know that,

Where,

Is the Binomial Coefficient.

It is given by:

It’s given that B (0) =1; B (1) =1; B (2) =2

Hence for n=3, from the first formulae

B (3) =C (2, K) B (K) where K=0 to n-1

B(3)=C(2,0)B(0)+ C(2,1)B(1)+ C(2,2)B(2)

From the second formulae, C (2, 0) =2! /0! (2-0) = 1

C (2, 1) =2; C (2, 2) =1

Hence,

B (3) =1*1+2*1+1*2=5

For n=4,

B(4)= C(3,0)B(0)+ C(3,1)B(1)+ C(3,2)B(2) + C(3,3)B(3)

        = 1*1+3*1+3*2+1*5= 15

Similarly,

For n=5,

B (5) = 52

For n=6,

B (6) = 203

Looking for the solutions of few mathematics questions?

a) ABC' + B C' D' + B C + C' D = B + C' D

Sol:

LHS = (ABC’+BC)+ (BC’D’+C’D)

       =B(C+C’A) +C’ (D+D’B)

       =B(C+A) +C’ (D+B)

       =AB+BC+C’D+C’B

      =AB+C’D+B (C+C’)                //C+C’=1

      =AB+C’D+B

      =B (1+A) +C’D                        //1+A=1

      =B+C’D

      =RHS

b) WY + W' Y Z' + WXZ + W' X Y' = WY + W' X Z' + X' Y Z' + X Y' Z

Sol:

RHS=wy + w’xz’ + x’yz’ + xy’z

        =WY(1+XZ)+ w’xz’(Y+Y’)+ x’yz’ (W+W’)+ xy’z(W+W’)         //Y+Y’=W+W’=1+XZ=1

        = wy + wxyz + w’xyz’ + w’xy’z’ +wx’yz’ + w’x’yz’ + wxy’z + w’xy’z

        =wy + w’xyz’ + w’x’yz’ + wxyz +wxy’z + w’xy’z + w’xy’z’ + wx’yz’

        =wy + wx’yz’ + w’yz’(x + x’) + wxz(y + y’)+w’xy’(z + z’)

        =wy(1 + x’z’) + w’yz’ + wxz + w’xy’

        = WY + W' Y Z' + WXZ + W' X Y'

        =LHS

c) A D' + A' B + C'D + B'C = (A' + B' + C' + D')(A + B + C + D') = AC’+A’B +B‘C + D’

Sol:

RHS=(A' + B' + C' + D')(A + B + C + D')

        =A’A+A’B+A’C+A’D’+B’A+B’B+B’C+B’D’+C’A+C’B+C’C+C’D’+D’A+D’B+D’C+D’D’

        =A’B+A’C+A’D’+B’A+B’C+B’D’+C’A+C’B+C’D’+D’A+D’B+D’C+D’   //AA’=0; D’D’=D’

        = AC’+A’B +B‘C + D’+ A’C (B+B’) + B’A (C+C’) + C’B (A+A’)    //A+A’=1

        = AC’ (1 + B’ + B) + A’B (1 + C’ + C) +B’C(1 + A + A’) + D’    //1+A=1

        = AC’+A’B +B‘C + D’

        =LHS

Chemistry Homework Help: How much more soluble is...

(a) How much more soluble is AgCl in 1 Molar NH3 than in water?
(b) How much more soluble is CaSO4 in 1 Molar HNO3 than in water?

Sol:

1) A chloride solution of metal reacts with silver nitrate solution to produce a precipitate. The precipitate is soluble in Ammonia solution:

Actually, NH3 complexes silver to make Ag (NH3)2, and this reaction is favorable enough to make AgCl dissolve (but not the much more insoluble Agcl. Hence Agcl is soluble in 1 molar NH3 to some extent.

2Agcl + 4NH3 ==> 2Ag (NH3)2 + cl2

2) CaSO4 is infinitely much more soluble in 1 molar HNO3. The reason is that the CaSO4 (mostly insoluble in water) is converted to Ca (NO3)2 which is very much soluble in water. As a result calcium sulphate is infinitely very much soluble in nitric acid.

CaSO4 +2HNO3 ==> Ca(NO3)2 + H2SO4

Write-Ups Assignment Help: What is a little-know secret to the profitability of Amazon.com?

The below are few of the topics on which the write-ups of 300 to 500 words are expected:

1) What is a little-know secret to the profitability of Amazon.com?

2) Which of these characterized the strategies is the early days (and somewhat, still today) of electronic commerce?

3)Q)“Words carry the message. They would carry the same meanings with or without paragraphing. Therefore, paragraphing has no effect on communication.” Discuss your view of this statement and provide an example which supports your analysis. 

4)What is access matrix? For what purpose is access matrix used in general purpose OS?

4)Many people feel that the American government is out of touch with its public. Look at the branches of government and analyze this statement. 

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Write-Ups Assignment Help: JIT logistics/supply chain management for what...

Q) JIT logistics/supply chain management for what (now defunct) America automaker.

Sol:

JUST-IN-TIME LOGISTICS SUPPORT IS USED FOR THE AUTOMOBILE INDUSTRY since JIT drastically reduces the investment as well as also the total cost of the operation. In the early 1970s the United States automobile industry realized that the advantage of adopting the JIT would bring the US automakers where they were carrying $775 worth of the work in the process inventory for each of the car they built, but the Japanese carried only $150 of the amount. The only very existence of the Unites states auto industry which depended on the adopting of the JIT philosophy. Very efficient way of transportation methods were one of the critical to the effective JIT process.

Key issues of the transportation before the JIT include plant locations, were the role of the transportation along with the deregulation as well as the transportation regulation. The placement of the plants also changed as a solution of the implementation of the JIT.

Networking Assignment Help: Explain the RSA Public Key Encryption Scheme in detail...

Q)Explain the RSA Public Key Encryption Scheme in detail.In particular ,how do the encryption and decryption algorithms work? Explain also how you choose the public and private keys.Suppose a user picks n=17*5; i.e .,p=17 and q=5.How should he pick the public key and the private key (i.e., d and e)? Give the encryption and decryption algorithms.

Sol:

RSA Public Key Encryption which was invented by Cocks (GCHQ), independently, by Rivest, Shamir and Adleman (MIT). Say for example let ‘p’ and ‘q’ is the two large prime numbers.

Let N = p*q be the modulus, then Choose ‘e’ relatively prime to (p-1)*(q-1)

Find d such that e*d = 1 mod (p-1)*(q-1)

Here the Public key is given by (N, e) and the Private Key is given by ‘d’.

The encryption as well as the decryption algorithm works as follows:

To encrypt the message M compute

C = M^e mod N

And to decrypt the message C compute

M = C^d mod N

Please recall that e and N are public, hence if attacker can factor N, then he can definitely use ‘e’ to easily find the value of ‘d’ since e*d = 1 mod (p-1)*(q-1)

Factoring the modulus will break the RSA, therefore it is not known that whether the factoring is the only one way to break RSA.

Suppose a user picks N=17*5; i.e., p=17 and q=5.

Hence N= 85,

(P-1)*(q-1) = 16*4=64

Choose ‘e’ such that it is relatively prime to 64. Hence e=5

Find‘d’ such that e*d = 1 mod 64, we find that d = 7 works

Public key: (N, e) = (85, 5)

Private Key: d = 7

Encryption as well as decryption algorithm works as follows:

Public key: (N, e) = (85, 5)

Private Key: d = 7

Suppose message M = 8

Cipher text C is computed as

C = M^e mod N = 8⁵ = 32768 = 17 mod 85

Decrypt C to recover the message M by

M = C^d mod N = 17⁷ = 410,338,673

= 12,434,505 * 85 + 8 = 8 mod 85

Homework Help: What is the speed of the block when the spring has been compressed...

A block with a mass of 0.148kg is traveling at 8.4m/s on a horizontal,frictionless surface when it hits a spring with a spring constant of 722 N/m. What is the compression of the spring when the block has slowed to 3.9 m/s?What is the speed of the block when the spring has been compressed by 0.049m?

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Physics Assignment Help: How much work is done moving a...

Q)How much work is done moving a 2.5 kg book to a shelf 3.0 m high?

a.What is the potential energy of the book in #7 above?
b.If the book in #7 above, falls off the shelf, how much kinetic energy will it have when it hits the floor

Sol:

Work done = Force*displacement

Force=m*g=2.5*9.8=24.5N

Work done= 24.5*3=73.5Joules

a) Potential energy = work done= m*g*h= 73.5Joules

b) Kinetic energy when it hits the floor will be at t=0,

V=U + at=0+9.8*0=0

KE= ½*m*v² = 0J

Chemistry Assignment Help: What is the equilibrium concentration of H2S...

Q)Kc = 2.6 × 10^8 at 825 K for the reaction

2H2(g) + S2(g) <===> 2H2S(g)

The equilibrium concentration of H2 is 0.0020 M and that of S2 is 0.0010 M. What is the equilibrium concentration of H2S?

1. 0.0010 M
2. 1.02 M
3. 10 M
4. 0.10 M

Sol:

K_c = [H2S]²/[H2]²*[S2]

2.6*10⁸ = [H2S]²/[0.002]²[0.001]

Hence equilibrium concentration of [H2S]= 1.02M

Chemistry Homework Help: what is the equilibrium concentration of...

Kc = 9.7 at 900 K for the reaction

NH3(g) + H2S(g) ---> NH4HS(s) .

If the initial concentrations of NH3(g) and H2S(g) are 2.0 M, what is the equilibrium concentration of NH3(g)?

1. 0.20 M
2. 1.7 M
3. 0.10 M
4. 0.32 M
5. 1.9 M

Sol:

K_c = [NH4HS]/[ NH3]*[ H2S]

At equilibrium the concentration of NH3 will be (2-x)

9.7=1/(2-x)²

Hence, 2-x = 0.32M

Physics Homework Help: Compare the kinetic energy of an...

Q) Compare the kinetic energy of an 900 kg car travelling at 30 m/s, and a 1,800 kg car at the same speed.

 Sol:

Kinetic energy is given by, KE = 1/2mv²

Where ‘m’ is the mass, ‘v’ is the velocity.

Case1:

Given m=900kg, v=30m/s

(KE) ₁= 0.5*900*30²=405000Joules

Case2:

Given m=1800kg,v=30m/s

(KE) ₂= 0.5*1800*30²=810000Joules

Therefore, (KE) ₂ = 2(KE) ₁

Write-Ups: Profiles can be defined to limit resource usage...

Q)Profiles are used to limit resources and implement password policies. Oracle implements password checking by defining a function to the database at login time. The default function provided by Oracle is implemented in a file.

Profiles can be defined to limit resource usage.

Why would you want to limit resource usage at all?

I would like the answer in about 150 words.

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Write-Ups: You have just been hired as an information security engineer for a large multi-international corporation...

Q) You have just been hired as an information security engineer for a large multi-international corporation. Unfortunately your company has suffered from multiple security breaches that have threaten the public's trust that their confidential data and financial assets are private and secured. Credit card information was compromised by an attacked who infiltrated the network through an vulnerable wireless connection within the organization and the other breach was an inside job, where personal data was stolen because of weak access control policies within the organization which allowed an unauthorized individual access to valuable data. Your job is to develop a risk management policy that addresses the two security breaches and how to mitigate these risks.

This assignment requires 2 to 3 pages in length (500 words minimum), based upon the APA style of writing.

Use transition words, thesis statement, Introduction, Body, Conclusion and Reference Page with at least two references. Double spaced Arial 12 Font.

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Homework Help: What is the instantaneous power delivered by the...

Q)A single constant force 25.1 N acts on a particle of mass 6.53 kg. The particle starts at rest at t = 0.
What is the instantaneous power delivered  by the force at t = 4.31 s?

Answer in units of W.

Sol:

Force, F=mass(m)*acceleration(a)

a= 25.1/6.53

 = 3.84m/s²

Instantaneous power delivered by the force at time t=4.31sec is given by,

P(t)= F(t)*V(t)

V(t)=U(t)+at

At t=4.31sec, U(t)=0

V(t)=3.84*4.31= 16.55m/s

Hence, P(t)= 25.1*16.55

           = 415.4W