ENGINEERING COLLEGE

The hot water needs of an office are met by heating tab water by a heat pump from 16 C to 50 C at an average rate of 0.2 kg/min. If the COP of this heat pump is 2.8, the required power input is: (a) 1.33 kW (d) 10.2 kW (b) 0.17 kW (c) 0.041 kW

Answers

Answer 1

Answer:

Answer:

option B

Explanation:

given,

heating tap water from 16° C to 50° C

at the average rate of 0.2 kg/min

the COP of this heat pump is 2.8

power output = ?

$COP = (Q_H)/(W_(in))\nW_(in) = (Q_H)/(COP)\nW_(in) = ((0.2)/(60)* 4.18* (50-16))/(2.8)\nW_(in) = 0.169$

the required power input is 0.169 kW or 0.17 kW

hence, the correct answer is option B

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In an adiabatic process, the temperature of the system remains constant. a)- True b)- False
The structure of a house is such that it loses heat at a rate of 5400 kJ/h per degree Cdifference between the indoors and outdoors. A heat pump that requires a power input of 6 kW isused to maintain this house at 21 C. Determine the lowest outdoor temperature for which the heatpump can meet the heating requirements of this house
A mass of 5 kg of saturated liquid-vapor mixture of water is contained in a piston-cylinder device at 125 kPa. Initially, 2 kg of the water is in the liquid phase and the rest is in the vapor phase. Heat is now transferred to the water, and the piston, which is resting on a set of stops, starts moving when the pressure inside reaches 300 kPa. Heat transfer continues until the total volume increases by 20%. (a) Determine the initial temperature. (b) Determine the final temperature. (c) Determine the mass of liquid water when the piston first starts moving. (d) Determine the work done during this process in kJ.
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Write a Lottery class that simulates a lottery. The class should have an array of five integers named lotteryNumbers. The constructor should use the Random class (from the Java API) to generate a random number in the range of 0 through 9 for each element in the array. The class should also have a method that accepts an array of five integers that represent a person’s lottery picks. The method is to compare the corresponding elements in the two arrays and return the number of digits that match. For example, the following shows the lotteryNumbers array and the user’s array with sample numbers stored in each. There are two matching digits (elements 2 and 4).

A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. Calculate the number of atoms in the unit cell and diameter of the metal atom.

Answers

Answer:288 pm

Explanation:

Number of atoms(s) for face centered unit cell -

Lattice points: at corners and face centers of unit cell.

For face centered cubic (FCC), z=4.

- whereas

For an FCC lattices √2a =4r =2d

Therefore d = a/√2a = 408pm/√2a= 288pm

I think with this step by step procedure the, the answer was clearly stated.

Use Newton's method to determine the angle θ, between 0 and π/2 accurate to six decimal places. for which sin(θ) = 0.1. Show your work until you start computing x1, etc. Then just write down what your calculator gives you.

Answers

Answer:

x3=0.100167

Explanation:

Let's find the answer.

Because we are going to find the solution for sin(Ф)=0.1 then:

f(x)=sin(Ф)-0.1 and:

f'(x)=cos(Ф)

Because 0<Ф<π/2 let's start with an initial guess of 0.001 (x0), so:

x1=x0-f(x0)/f'(0)

x1=0.001-(sin(0.001)-0.1)/cos(0.001)

x1= 0.100000

x2=0.100000-(sin(0.100000)-0.1)/cos(0.100000)

x2=0.100167

x3=0.100167

A 100-mm-diameter cast Iron shaft is acted upon by a 10 kN.m bending moment, a 8 kN.m torque, and a 150 kN axial force simultaneously. The ultimate tensile strength of the shaft material is 210 MPa, and the ultimate compressive strength of the shaft material is 750 MPa, determine the safety factor against failure for the above types of loading using a proper theory of failure.

Answers

Answer:

Are you smart You seem smart

Explanation:

im ur dad

Can anyone tell me all the corrects answers to these? I’m sorry if this is the wrong subject I’m not sure what to put it under but I really need help!

Answers

Answer:

Crankshaft position sensor - F I can't quite make out the letter but it's the thing at the bottom almost touching the notched wheel.

Coil Module - B

Knock Sensor - D

Coil Pack -E

Fuse Block - A

Powertrain Control Module - C

A 78-percent efficient 12-hp pump is pumping water from a lake to a nearby pool at a rate of 1.5 ft3/s through a constant-diameter pipe. The free surface of the pool is 32 ft above that of the lake. Determine the irreversible head loss of the piping system, in ft, and the mechanical power used to overcome it. Take the density of water to be 62.4 lbm/ft3.

Answers

Answer:

irreversible head loss is 38.51 ft

mechanical power 6.55 hp

Explanation:

Given data:

Pump Power 12 hp = 8948.39 watt = 6600 lbs ft/sec

Q = 1.5 ft^3/s

Pump actually delivers $P' = \eta P = 0.78 * 8948.39 = 6979.74 watt$

Power that water gains $= mgh = \rho \phi gh = r \phi h$

$P = 62.4 * 1.5 * 32 = 2995.2 lbs ft/sec$

hence Power lost = 6600 - 2995.2 3604.8 lbs ft/sec = 6.55 hp

head loss $hl = (3604.8)/(r \phi) = (3604.8)/(62.4 * 1.5)$

hl = 38.51 ft

Calculate how large a mass would be necessary to obtain a mechanical noise limit of [Equation] = 1 nG, 1 µG, and 1 mG if the mechanical resonance frequency is [Equation] = 100 Hz. If the mass is to be made of cube of `silicon, what would its physical dimensions be?

Answers

Answer:

Mechanical resonance frequency is the frequency of a system to react sharply when the frequency of oscillation is equal to its resonant frequency (natural frequency).

The physical dimension of the silicon is 10kg

Explanation:

Using the formular, Force, F = 1/2π√k/m

At resonance, spring constant, k = mw² ( where w = 2πf), when spring constant, k = centripetal force ( F = mw²r).

Hence, F = 1/2π√mw²/m = f ( f = frequency)

∴ f = F = mg, taking g = 9.8 m/s²

100 Hz = 9.8 m/s² X m

m = 100/9.8 = 10.2kg

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