Answer:
The mechanical efficiency of the pump is 91.8 %
Explanation:
Given;
input power, p = 44 kw
density of oil, ρ = 860 kg/m³
motor efficiency, η = 90 %
inlet diameter, d₁ = 8 cm
outlet diameter, d₂ = 12 cm
volume flow rate, V = 0.1 m³/s
pressure rise, P = 500kPa
output power = motor efficiency x input power
output power = 0.9 x 44 = 39.6 kW
Thus, the mechanical input power = 39.6 kW
The mechanical output power is given by change in mechanical energy;
[tex]E = mgh + \frac{m}{2} (v_2^2 - v_1^2) \\\\E = \rho V g h + \frac{\rho V}{2} [(\frac{V_2}{\pi r_2^2} )^2 - (\frac{V_1}{\pi r_1^2})^2]\\\\E = PV + \frac{\rho V^3}{2\pi^2} [\frac{1}{ r_2^4} - \frac{1}{ r_1^4}]\\\\E = (500 *10^3)(0.1) + \frac{(860)(0.1)^3}{2\pi^2} [\frac{1}{ 0.06^4} - \frac{1}{ 0.04^4}]\\\\E = 50000 -13653.51\\\\E = 36346.48 \ W\\\\E = 36.347 \ kW[/tex]
The mechanical efficiency is given by
η = mechanical output power / mechanical input power
η = 36.347 / 39.6
η = 0.918
η = 91.8 %
Therefore, the mechanical efficiency of the pump is 91.8 %
A wire 6.60 m long with diameter of 2.05 mm has a resistance of 0.0310 Ω.
Find the resistivity of the material of the wire.
rho= Ω*m
Answer:
1.551×10^-8 Ωm
Explanation:
Resistivity of a material is expressed as shown;.
Resistivity = RA/l
R is the resistance of the material
A is the cross sectional area
l is the length of the wire.
Given;
R = 0.0310 Ω
A = πd²/4
A = π(2.05×10^-3)²/4
A = 0.000013204255/4
A = 0.00000330106375
A = 3.30×10^-6m
l = 6.60m
Substituting this values into the formula for calculating resistivity.
rho = 0.0310× 3.30×10^-6/6.60
rho = 1.023×10^-7/6.60
rho = 1.551×10^-8 Ωm
Hence the resistivity of the material is 1.551×10^-8 Ωm
6. What is Mass????????????????
If a person is standing up in a moving bus that stops suddenly,the person can easily fall forwards.Has a force acted to push the person forwards? Use Newton's law of motion to explain what is happening.
Answer:
i think gravity created a force strong enough to push him down.but it also depends how slow or fast the bus is going
Explanation:
gravity as we all now it is pretty strong so if the bus is going fast then the person standing up will fall but if the bus is going pretty slow then it'll just nudge him.
13.
14. Why does a person feel weightlessness during freefall?
Answer:
When in free fall, the only force acting upon your body is the force of gravity - a non-contact force. Since the force of gravity cannot be felt without any other opposing forces, you would have no sensation of it. You would feel weightless when in a state of free fall.
A nucleus with a mass number of 64 has a mean radius of about: _________.
A. 4.8 fm.
B. 19 fm.
C. 77 fm.
D. 260 fm.
E. 2.6 × 10 5 fm
Answer:
The correct option is A
Explanation:
From the question we are told that
The mass number is [tex]A= 64[/tex]
Generally the mean radius is mathematically evaluated as
[tex]R = R_o A^{\frac{1}{3} }[/tex]
Here [tex]R_o[/tex] is a constant with a value [tex]R_o =1.2*10^{-15}[/tex]
So
[tex]R = 1.2*10^{-15} * 64^{\frac{1}{3} }[/tex]
[tex]R = 4.8 *10^{-15} [/tex]
[tex]R = 4.8\ fm [/tex]
The mean radius of a nucleus with the given mass number is 4.8 fm.
Hence, Option A. 4.8 fm is the correct answer.
Given the data in the question;
Mass number of nucleus; [tex]A = 64[/tex]
Mean radius; [tex]R =\ ?[/tex]
The volume of the nucleus is directly proportional to the total number of nucleons.
The radius of a nucleus, R, is approximately:
[tex]R = R_oA^{\frac{1}{3} }[/tex]
Where R is the radius, R₀ is constant for all nuclei ([tex]1.2*10^{-15}m \ or\ 1.2fm[/tex] ) and A is the mass number.
We substitute our values into the equation
[tex]R = 1.2fm\ *\ 64^{\frac{1}{3} }\\\\R = 1.2fm\ *\ 4\\\\R = 4.8 fm[/tex]
The mean radius of a nucleus with the given mass number is 4.8 fm.
Hence, Option A. 4.8 fm is the correct answer.
Learn more: https://brainly.com/question/1371394
I need help ASAP plzzz!!!!
Answer:
1. coffee maker 2.store B. 3.yes 5. 180
This ball is technology too! It can be
rolled, kicked, or thrown. Is that a need
or a want?
Answer:
want
Explanation:
people always want the new thing especially if its technology
A baseball pitcher's average fastball pitch speed is 98.6 mph. What is that speed in
m/s?
Answer:
44.078 m/s
Explanation:
convert 98.6 miles to meters then convert the hour to minutes and minutes to seconds
Scientific notation: Convert 7.1 x 10-3 to decimal notation.
Answer: hey
your answer is gonna be
71000.
Explanation:
360 s to ms? Need help! Converting units, with work pls
1 s = 1,000 ms
2 s = 2,000 ms
3 s = 3,000 ms
.
.
10 s = 10,000 ms
20 s = 20,000 ms
30 s = 30,000 ms
.
.
.
100 s = 100,000 ms
200 s = 200,000 ms
300 s = 300,000 ms
310 s = 310,000 ms
320 s = 320,000 ms
.
.
.
350 s = 350,000 ms
360 s = 360,000 ms
370 s = 370,000 ms
.
.
.
Nami conducts an investigation on plants. She places a grow light on a timer to give the plants different amounts of light to see if this would affect their growth. Which term describes the amount of light in this investigation?
Answer:
It is independent variable
Explanation:
Answer:
D!!!!!
Explanation:
edge 2021!
What is the speed of an object that travels 60 meters in 4 seconds?
Answer:
15 m/s
Explanation:
s=d/t
s=60/4
s=15 m/s
Answer:
The answer would be 15 m/s
Explanation:
s=d/t
s=60/4
s= 15 m/s
Have a beautiful day beautiful
You welcome.
Acceleration occurs when velocity changes. O True O False
Answer:
True
Explanation:
Acceleration by definition is the change in velocity divided by the change in time. Thus when the velocity changes, there must be an acceleration.
Two satellites orbit earth at altitudes of 7500 km and 15000 km above earth's surface. Which satellite is faster and by what factor?
Answer:
The satellite that is 7500 km above earth's surface is 1.24 times faster than the satellite at 15000 km above earth's surface
Explanation:
Generally the gravitational force acting on each satellite is mathematically represented as
[tex]F = \frac{G * M_e * m_2 }{r^2}[/tex]
Here [tex]M_e[/tex] is the mass of the earth
[tex]r = r_e + R [/tex]
So [tex] r_e [/tex] is the radius of the satellite and R is the radius of earth with value R = 6371 km
This force is also equivalent to the centripetal force acting on each satellite which is mathematically represented as
[tex]F = \frac{mv^2}{ r^2}[/tex]
So
[tex]\frac{mv^2}{ r^2} = \frac{G * m_1 * m_2 }{r^2}[/tex]
=> [tex]v = \sqrt{ \frac{GM_e}{r} }[/tex]
So for [tex]r = 7500+ 6371 = 13871 \ km [/tex]
We have that
[tex]v_1 = \sqrt{ \frac{GM_e}{13871} }[/tex]
and [tex]r = 15000+ 6371 = 21371 \ km [/tex]
We have that
[tex]v_2 = \sqrt{ \frac{GM_e}{21371} }[/tex]
So
[tex]\frac{v_1}{v_2} = \frac{\sqrt{\frac{GM_e}{13871} } }{ \sqrt{\frac{GM_e}{21371}} }[/tex][tex]v = \sqrt{ \frac{GM_e}{r} }[/tex]
=> [tex]\frac{v_1}{v_2} = \sqrt{ \frac{21371}{13871} }[/tex]
=> [tex]v_1 = 1.24 v_2[/tex]
So satellite that is 7500 km above earth's surface is 1.24 times faster than the satellite at 15000 km above earth's surface
How is newton's third law different from newton's first law
Answer : Newton's first law of motion (also known as Law of Inertia) describes about the tendency of an object to resist change from its state of rest / motion / direction (inertia).
Whereas, Newton's third law of motion tells us that forces exists in pairs. It talks about the action & reaction forces, which are equal in magnitude but opposite in direction.
In this way, Newton's third law of motion is different from Newton's first law of motion.
A bucket is being lowered by a very light rope with a constant downward velocity. The tension in the rope must be
Answer:
The tension in the light rope must be equal to the weight of the bucket
Explanation:
Given that,
Constant velocity of bucket and direction of bucket in downward
We need to find the tension in the rope
Using given data,
When a bucket moves downward with a constant velocity then the net force does not applied on the bucket.
So, The weight of the bucket will be equal to the tension in the light rope
In mathematically,
[tex]T=mg[/tex]
Where, T = tension
m = mass of bucket
g = acceleration due to gravity
Hence, The tension in the light rope must be equal to the weight of the bucket.
Is steel considered matter
Answer:
yes. everything around you is matter including you!
Answer:
yes
Explanation:
because it takes up space
Protons are launched with an initial speed 9550 m/s at 37° above the horizontal, into a region where a uniform vertical electric field is present. The protons hit a target at a horizontal distance 1.27 mm from the point where the protons are launched. Find the electric field, the time of flight, and the maximum height reached by the protons above the point where they were launched.
Answer:
E=720,5 N/C
H=0,24mm
Explanation:
The foundation of psychology is?
Case Studies
O Experiments
O Research
O Analysis
Answer:
Case Studies
Explanation:
A case study in psychology is a descriptive research approach used to obtain in-depth information about a person, group, or phenomenon.Case studies use techniques such as personal interviews, direct observation, psychometric tests, and archival records to gather information.
The position of a particular particle as a function of is given by r=(8.5t i+5.6j-2tk )m (a) Determine the particle’s velocity and acceleration as a function of time.
(b) Find the instantaneous velocity and acceleration of the particle at t=3.0 s.
Answer:
use google to find answer
Explanation:
69 69 69 69 69 69
Organized procedure to study something under controlled conditions
can anyone help me with this.
Answer:
A. smaller arteries
Explanation:
A. because it makes no sence.
is the
What is the tendency to move to a drive-free state?
O A. Homeostasis
OB. Equality
OC. Homogeneity
OD. Motivationless
A train rounding a curve at a steady speed, balanced or unbalanced force?
Answer:
Unbalanced
Explanation:
It would be speeding and under the influence of an imbalanced force if it were rounding a curve. The train must be subject to an unbalanced force in order for it to continue moving at a constant speed.
What curves a steady speed, balanced or unbalanced force?Newton's first law is only this one. Unless operated upon by an imbalanced force, an item at rest remains at rest and an object in motion maintains constant speed in the same direction.
The car tends to maintain its travel at a steady speed and direction because the two forces balance each other out and cancel each other out.
The forces are out of balance when an object's motion changes. Equal in size and directed in the opposite direction, balanced forces are. When forces are evenly distributed, motion remains unchanged.
Therefore, One of your scenarios from the previous section involved pushing or pulling an object with the equal amount of force in opposite directions.
Learn more about force here:
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If all other things remain equal, which of the following changes to a closed circuit
would result in increased resistance to the flow of electric current?
Reducing the temperature of the conductor
Reducing the thickness of the conductor
Replacing the conductor with a more conductive material
Reducing the length of the conductor
Answer:
the answer is b reducing the thickness of the conductor
Explanation:
The resistance to electric current increases as the cross-section of the conductor is reduced, as the conductor is lengthened, and as the conductor is heated. Replacing the conductor with a less-conductive material increases the resistance as well.
Answer:
Reducing the thickness of the conductor
Explanation:
Calculate the average speed between 0 s and 20 s
Answer:
2 m/s
Explanation:
The following data were obtained from the question:
Distance (D) = 40 m
Time (t) = 20 s.
Average speed =?
Average speed is the total distance travelled divided by the total time taken. Mathematically, it is expressed as:
Average speed = Total distance /Total time
Thus, we can obtain the average speed as follow:
Total Distance (D) = 40 m
Time time (t) = 20 s.
Average speed =?
Average speed = Total distance /Total time
Average spee= 40/20
Average speed = 2 m/s
Therefore, the average speed between 0 and 20 seconds is 2 m/s.
To understand the decibel scale. The decibel scale is a logarithmic scale for measuring the sound intensity level. Because the decibel scale is logarithmic, it changes by an additive constant when the intensity as measured in W/m2 changes by a multiplicative factor. The number of decibels increases by 10 for a factor of 10 increase in intensity. The general formula for the sound intensity level, in decibels, corresponding to intensity I is
The question is incomplete. Here is the complete question.
To understand the decibel scale. The decibel scale is a logarithmic scale for measuring the sound intensity level. Because the decibel scale is logarithmic, it changes by an additive constant when the intensity when the intensity as measured in W/m² changes by a multiplicative factor. The number of decibels increase by 10 for a factor of 10 increase in intensity. The general formula for the sound intensity level, in decibels, corresponding to intensity I is
[tex]\beta=10log(\frac{I}{I_{0}} )dB[/tex],
where [tex]I_{0}[/tex] is a reference intensity. for sound waves, [tex]I_{0}[/tex] is taken to be [tex]10^{-12} W/m^{2}[/tex]. Note that log refers to the logarithm to the base 10.
Part A: What is the sound intensity level β, in decibels, of a sound wave whose intensity is 10 times the reference intensity, i.e. [tex]I=10I_{0}[/tex]? Express the sound intensity numerically to the nearest integer.
Part B: What is the sound intensity level β, in decibels, of a sound wave whose intensity is 100 times the reference intensity, i.e. [tex]I=100I_{0}[/tex]? Express the sound intensity numerically to the nearest integer.
Part C: Calculate the change in decibels ([tex]\Delta \beta_{2},\Delta \beta_{4}[/tex] and [tex]\Delta \beta_{8}[/tex]) corresponding to f = 2, f = 4 and f = 8. Give your answer, separated by commas, to the nearest integer -- this will give an accuracy of 20%, which is good enough for sound.
Answer and Explanation: Using the formula for sound intensity level:
A) [tex]I=10I_{0}[/tex]
[tex]\beta=10log(\frac{10I_{0}}{I_{0}} )[/tex]
[tex]\beta=10log(10 )[/tex]
β = 10
The sound Intensity level with intensity 10x is 10dB.
B) [tex]I=100I_{0}[/tex]
[tex]\beta=10log(\frac{100I_{0}}{I_{0}} )[/tex]
[tex]\beta=10log(100)[/tex]
β = 20
With intensity 100x, level is 20dB.
C) To calculate the change, take the f to be the factor of increase:
For [tex]\Delta \beta_{2}[/tex]:
[tex]I=2I_{0}[/tex]
[tex]\beta=10log(\frac{2I_{0}}{I_{0}} )[/tex]
[tex]\beta=10log(2)[/tex]
β = 3
For [tex]\Delta \beta_{4}[/tex]:
[tex]I=4I_{0}[/tex]
[tex]\beta=10log(\frac{4I_{0}}{I_{0}} )[/tex]
[tex]\beta=10log(4)[/tex]
β = 6
For [tex]\Delta \beta_{8}[/tex]:
[tex]I=8I_{0}[/tex]
[tex]\beta=10log(\frac{8I_{0}}{I_{0}} )[/tex]
β = 9
Change is
[tex]\Delta \beta_{2},\Delta \beta_{4}[/tex], [tex]\Delta \beta_{8}[/tex] = 3,6,9 dB
Air conditioners operate on the same principle as refrigerators. Consider an air conditioner that has 7.00 kg of refrigerant flowing through its circuit each cycle. The refrigerant enters the evaporator coils in phase equilibrium, with 54.0 % of its mass as liquid and the rest as vapor. It flows through the evaporator at a constant pressure and when it reaches the compressor 95% of its mass is vapor. In each cycle, how much heat Qc is absorbed by the refrigerant while it is in the evaporator? The heat of vaporization of the refrigerant is 1.50×105 J/kg
Answer:
5.15J
Explanation:
First. 54% of the 7kg refrigerant is liquid
So we find mass of vapour at inlet generator
M1 = ( 1-0.54)*7= 3.2kg
At compressor mass of vapour will be
M2= 0.95*7= 6.7kg
So the Mass of vapour at exit generator is
M2-M1= 3.5kg
So to find heat absorbed by refrigerant in evaporation
Its using
Q= mh
°= 3.5x 1.50×10^5 J/kg
=5.15J
The various types of tree sloths share the honor of being the slowest-moving
mammals. An average tree sloth moves with a speed of 0.743 m/s. How long does it
take a sloth moving at this speed to travel 22.30 m?
Answer:
16.568 Minutes
Explanation:
Time = speed (m/s) x distance (m)
Let's start by calculating what acceleration the rocket must produce to launch into earth orbit. In order to attain orbit around earth, the ATLAS V rocket must accelerate up to a speed of about 7700 meters per second in about 4.2 minutes. What average acceleration is required to accomplish this
Answer:
30.56 m/s^2
Explanation:
Given that In order to attain orbit around earth, the ATLAS V rocket must accelerate up to a speed of about 7700 meters per second in about 4.2 minutes.
The average acceleration that is required to accomplish this will be
Average acceleration = change in velocity / time
Average acceleration = 7700/ 4.2 × 60
Average acceleration = 7700/252
Average acceleration = 30.56 m/s^2