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.

Assignment Help: Phases of the Moon Exercise...

In this exercise, you will investigate the cause of the phases of the Moon. The figure below shows an orbital diagram of the Earth-Moon system as viewed from above the Earth's north pole. Light from the Sun is coming from the left. Note that the drawing is not to scale.

Section I

Shade in the part of the Moon that is in shadow and the part that is not observable from Earth in each of the eight numbered positions. The first has been completed as an example. (Use dark shading for the shadow, light cross-hatch for the unobservable side.) 

To be continued based on the request, please feel free to contact us or comment on this post for more info on this question/answer

Homework Help: What is the rms speed of each helium atom...

Q)The molecular mass of helium is 4 g/mol, the Boltzmann’s constant is 1.38066 ×
10−23 J/K, the universal gas constant is 8.31451 J/K · mol, and Avogadro’s number
is 6.02214 × 1023 1/mol. Given: 1 atm = 101300 Pa.
What is the rms speed of each helium atom?
Answer in units of m/s.

Sol:

The average kinetic energy is given by:

KE_atom = (PV)/N

Number of atoms (N)= Avogadro's number (A) * n
where N = A*n = A*(PV/RT)

N = 6.02214 x 10^23 atoms/mole * (96235 Pa * 0.01414 m^3) / (8.31451 J/K-mol * 285.15 K)
N = 3.456 x 10^23 atoms

KE_atom = (96235*0.01414 /3.456 x 10^23 )J/atom
      = 3.94 X 10^-21 J/atom

KE_a = (1/2) m v^2
m = (Molecular Mass (Mm) / A)
m = (0.004 kg/mole / 6.02214 x 10^23 atoms/mole)
m = 6.42 x 10^-27 kg/atom
v^2 = (2 KE_a)/m
v = sqrt((2 KE_a) / m)
v = sqrt((2 * 3.94 X 10^-21 J/atom) / 6.42 x 10^-27 kg/atom)
v = 1108 m/s

Chemistry Homework Help: How many atoms of helium gas are required to fill a balloon to diameter..

Q)The molecular mass of helium is 4 g/mol, the Boltzmann’s constant is 1.38066 ×
10−23 J/K, the universal gas constant is 8.31451 J/K · mol, and Avogadro’s number
is 6.02214 × 1023 1/mol. Given: 1 atm = 101300 Pa.
How many atoms of helium gas are required to fill a balloon to diameter 30 cm at 12◦C and 0.95 atm?

Sol:

PV = nRT
n = PV/RT
Number of atoms (N)= Avogadro's number (A) * n
N = A*n = A*(PV/RT)
P = 0.95 * 101300 Pa
P = 96235 Pa
V = (4/3) pi R^3
R = 0.15 m
V = (4/3) pi (0.15 m)^3
V = 0.01414 m^3
T = 273.15 + 12
T = 285.15 K

N = 6.02214 x 10^23 atoms/mole * (96235 Pa * 0.01414 m^3) / (8.31451 J/K-mol * 285.15 K)
N = 3.456 x 10^23 atoms

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

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

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

Homework Help: What is the gauge pressure in the tire after a ride on a hot day when the tire....

The tire on a bicycle is filled with air to a gauge pressure of 647 kPa at 20◦C. What is the gauge pressure in the tire after a ride on a hot day when the tire air tempera- ture is 69◦C? (Assume constant volume and a constant atmospheric pressure of 101.3 kPa.)
Answer in units of kPa.

Sol:
Here the formulae used is:

P1V1=n1RT1
P2V2=n2RT2

Where P1=po+pg
P1=101.3kPa + 647kPa= 748.3kPa
n1=n2
also given that V1=V2.
Hence, P1/T1=nR/V=P2/T2
P1/P2=T1/T2
or
P2=(P1*T2)/T1 = (748.3 *(273+69))/(273+20)
P2=748.3kPa(342K/293K)= 748.3kPa * (1.167)=873.44kPa

Homework Help: what is the new pressure in the tank?

Gas is confined in a tank at a pressure of 10 atm and a temperature of 13◦C. If 38 percent of the gas is withdrawn and the temperature iGas is confined in a tank at a pressure of 10 atm and a temperature of 13◦C. If 38 percent of the gas is withdrawn and the temperature is raised to 70◦C, what is the new pressure in the tank? Answer in units of atm.s raised to 70◦C, what is the new pressure in the tank?
Answer in units of atm.

Sol:

Here we will make use of the formulae:

P2 = P1*(V1/V2)*(T2/T1), where V2 = 0.62(V1), T1= 13+273= 286K

T2= 70+273= 343

P2 = 10*1.6129*343/286 = 19.34atm

Homework Help: what is canonical commutation of..

Q)  what is canonical commutation of [p^2,q^2]

Sol:

Hence canonical computation of [p², q²] = (2ip)*(-2iq)

                                        = 4pq, since i²= -1

SQL Homework Help: Could you write the SQL commands that would implement this profile...

#User profiles
Your company has hired several new people for a new department project in your regions. This department will have some different requirements from regular works, and the DBA wants to ensure that the new hires will not be getting stepped on by current users in the database and vise versa. To help insulate the new hires, it has been decided to create a specific profile for them. The profile name will be NEWREG1 and it will need to have the following properties:

* After three login attempts, the account should be locked.
* The password should expire after 30 days.
* The same password should not be reused again for at 31 days.
* The account should have a grace period of five days to change an expired password.
* Each user can have 3 concurrent sessions open.

Could you write the SQL commands that would implement this profile. Next, write the query that would list the profile, the profile resource name, and the limit value for the new profile.

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Homework Help: The coefficient of performance for refrigerators....

Q) The coefficient of performance for refrigerators is defined as K = qc / w. It is also known as Tcold / Thot - Tcold.

What happens to K reversible as Tc (temp cold) goes to 0k?

Sol:

K = T_cold/(T_hot-T_cold)

K reversible means 1/K

Hence 1/K= (T_hot-T_cold)/ T_cold

              = (T_hot/ T_cold)-( T_cold/ T_cold)

         =  (T_hot/ T_cold)- 1

By neglecting 1, which is a small value, we get

1/K directly proportional to 1/ T_cold

Hence as T_cold goes to 0k, K reversible tends to infinity, a very large value.

Assignment Help: Derive an expression for link utilization...

Q) Derive an expression for link utilization U of a data link that uses the sliding-window flow control and returns an ACK for every OTHER frame received. Assume error free transmission. Link length is d, propagation velocity is v, frame size is L, and window size is W.

Need a quick solution to this question? Comment on this post!!!

HomeWork Help: Count back from the secondary after the last frame? Assume error-free operation..

Q) Assume that the primary HDLC station in NRM has sent six I-frames to a secondary. The primary’s N(S) count was three(011 binary) prior to sending the six frames. If the poll bits are in the sixth frame, what will be the N(R) count back from the secondary after the last frame? Assume error-free operation.

Need a quick solution to this question? Comment on this post!!!

HomeWork Help: What is the current in the bulb..

Q) A 100 W lightbulb is plugged into a standard 120 V outlet. (a) How much does it
cost per 31-day month to leave the light turned continuously? Assume electrical
energy costs US$0.06/kWh. (b) What is the resistance of the bulb? (c) What is the current in the bulb?

Sol:

First let us find the energy used in 31 days is(in kWh) and then let go for calculating the cost.

a) U = P * t = 0.100kW * 31days * 24hrs/day

       = 74.4kWh

Cost per 31 day month = 74.4kW h * $0.06/kW h

  = $4.464

b) The resistance of the bulb is given by,

P = V²/R

R = V²/P

  = (120V)²/100W

=144Ω

c) The current in the bulb is given by,

P = VI

I = P/V

     = 100W/120V

 = 0.833 A

Assignment Help: How much thermal energy is produced in..

Q) A 1250 W radiant heater is constructed to operate at 115 V. (a) What is the current in
the heater when the unit is operating? (b) What is the resistance of the heating coil? (c)
How much thermal energy is produced in 1.0 h?

Sol:

a) We can calculate the current ‘I’ from the power and voltage.

P = IV

I = P/V

= 1250/115

=10.87A

b) We can calculate the Resistance ‘R’ from the Voltage and power

P = V²/R

R = V²/P

= (115)²/1250

=10.58ohms

c) Thermal energy ‘U’ produced in 1 hr=3600secs is given by,

U = P * t =1250 *3600 = 4.5 *10⁶J