Answer:
HI
Explanation:
its E
Electric power is to be generated by installing a hydraulic turbine-generator at a site 70 m below the free surface of a large water reservoir that can supply water at a rate of 1500 kg/s steadily. If the mechanical power output of the turbine is 800 kW and the electric power generation is 750 kW, determine the turbine efficiency and the combined turbine–generator efficiency of this plant. Neglect losses in the pipes.
Answer:
[tex]\eta_{turbine} = 0.777 = 77.7\%[/tex]
[tex]\eta_{combined} = 0.728 = 72.8\%[/tex]
Explanation:
First we calculate the power input to the turbine. The input power will be equal to the potential energy of water per unit time:
Input Power = [tex]P_{in} = \frac{Work}{Time} = \frac{Potential\ Energy\ of\ Water}{t} \\P_{in} = \frac{(mass)(g)(height)}{Time} = (mass flow rate)(g)(height)\\\\P_{in} = (1500\ kg/s)(9.81\ m/s^2)(70\ m)\\P_{in} = 1.03\ x\ 10^6\ W = 1030\ KW[/tex]
Now, for turbine efficiency:
[tex]\eta_{turbine} = \frac{Mechanical\ Power\ Out}{P_{in}}\\\\\eta_{turbine} = \frac{800\ KW}{1030\ KW}\\\\\eta_{turbine} = 0.777 = 77.7\%[/tex]
for generator efficiency:
[tex]\eta_{generator} = \frac{Power\ Generation}{Mechanical\ Power\ Out}\\\\ \eta_{generator} = \frac{750\ KW}{800\ KW}\\\\\eta_{turbine} = 0.9375 = 93.75\%[/tex]
Now, for combined efficiency:
[tex]\eta_{combined} = \eta_{turbine}\ \eta_{generator}\\\\\eta_{combined} = (0.777)(0.937)\\\eta_{combined} = 0.728 = 72.8\%[/tex]
41. What effects the efficiency of a pulley?
a. the type of rope or cable
b. the way the wheel turns
c. the length of the rope
d. how big the wheel is
e. only a and be
f. all of the above
Answer:
e. only a and b
type of energy found in bread
Answer:
Bread contains energy in form of
Carbohydrates
Explanation:
Answer:
CHEMICAL ENERGY
An object weighing 49 N is pushed across a floor by a force of 12 N. What is the acceleration of the object?
Answer:
Explanation:
Given parameters:
Weight of object = 49N
Force applied = 12N
Unknown:
Acceleration of object = ?
Solution:
The acceleration of the object is found by dividing the force by the weight;
Acceleration = [tex]\frac{12}{49}[/tex] = 0.25m/s²
PLZ HELP ME
Which event was a major source of atmospheric oxygen?
photosynthesis
decomposition of water
volcanic eruptions
outgassing
Answer:
photosynthesis
Explanation:
I just took the midterm and got it correct :))
PLZ MAKE BRAINLIEST, thank youuu <3
A duck is floating in a pond. How does Archimedes' description of the buoyant force explain why the duck
doesn't sink?
PLEASE HURRY
Answer:
The upthrust or buoyant force helps the duck doesn't sink.
For example, there is a duck which weighs 3 pounds and tree pints of water also weigh three pounds. In this case the volume of the duck is more than the volume of three pints of water, so the duck floats.
Hope it helps!<3
Which of the following is the keyboard shortcut for saving a document?
O Control V
O Control S
O Control A
O Control E
Answer:Control S, Command S on MAC=Save
Help please!!!
if superman at 90kg jumps a 40m building in a single bound how much work does superman perform
Answer:
5 years worth of work (aka all of the homework i currently have)
help me do this question
Answer:
c20800
Explanation:
go to bear khana bro your book looks cheap go and study in durbar kanda school and take somee cash and do ash ah boy
A car with a mass of 1600 kg is towing a trailer with a mass of 420 kg. The car
provides a forward thrust of 3300 N. What is the acceleration of the trailer?
Answer:
1.63366
Explanation:
I got this answer from calculator soups physics calculators. I really recommend their website for formulas.
what power is transmitted by 2A flowing across 5V
Answer:
[tex]\huge\boxed{10\:watts}[/tex]
Explanation:
Power = Current × Voltage
P = I × V
P = 2 × 5
P = 10 watts
Which is true of the greenhouse effect?
A. It is purely a manmade phenomenon.
B. it does not involve carbon dioxide.
C. It causes cooling of Earth's atmosphere.
C. it traps thermal energy from the Sun.
Answer:
c is correct option thanks to brainly
Write 2 laws of reflection of light
Answer:
Answer⤵i)The first law of reflection states that the incident ray, the reflected ray, and the normal to the surface of the mirror, all lie in the same plane. ii)The second law of reflection states that the angle of reflection is equal to the angle of incidence. Both angles are measured with respect to the normal to the mirror.Which type of air mass forms over the ocean near the equator?
A
moist and warm
B
moist and cool
C
dry and warm
D
dry and cool
Answer:
a
Explanation:
A stone takes 5.4 seconds to fall from the top of a cliff. The cliff is
meters high.
143
53
286
573
Answer:
143
Explanation:
Using one of the 3 fundamental equations in physics, y=vo*t+1/2gt^2, we can use this equation to find the total distance that was traveled.
Acceleration due to gravity is always 9.8m/s^2 and time is 5.4s, we also have no initial velocity.
Given this, we can plug in the known variables.
y=0t+1/2*9.8*5^2
simplify,
y=4.9*5.4^2
y=4.9*29.16
y=142.884m which we can round up to 143 meters
Final Answer: 143 meters
A pulse with a height of 20 cm and a length of 30 cm travels with a speed of 400 cm/s through a spring that has been stretched so it is 800 cm long. If we want to send another pulse through the spring that will have a different speed, which of the bolded words should we change? List all that will change the speed of the wave.
Answer:
To send a pulse of different speed, change the tension or stretch on the spring
Explanation:
A pulse is a single disturbance of a particle is a medium. The pulse has an amplitude or and a pulse length in the medium. The speed of the pulse is dependent on the amount of strain or tension ( stretch) applied to the medium. The speed also determines the length of the pulse but is unaffected by the or amplitude of the pulse.
A rat runs 2m right, turns around and runs 3m left. Then goes 2m right. What is its displacement?
A. 1m right
B. 1m left
C. 7m
D. 7m left
Answer:
Explanation:
I think this answer would be 1m to the left.
The force of air particles over an area is ________
temperature.
pressure.
volume.
kelvins.
What is the difference between the geographic North Pole and the magnetic north pole?
Answer:
Magnetic north is the direction towards the north magnetic pole, which is a wandering point where the Earth's magnetic field goes vertically down into the planet
Explanation:
I searched it up lol
Should the resistance of an ammeter low or high ?give reason
Answer:
The resistance of an ammeter should be low. This is because an ammeter is connected in series with the circuit for the measurement of electric current. In case, its resistance is high, then some amount of current may lost in heating it leading to the inaccurate reading. An ideal ammeter is one which has zero resistance.
These the flow of electrons (the current) and where some of electrons energy gets converted into heat
a. electric currents
b. Insulators
c. Resistors
e. conductors
A weightlifter completes a series of lifts with a 700 N weight. In one lift, he raises the weight to a height of 2.5 m off the ground. The lift takes 0.60 s to complete. What power does the weightlifter have been performing this lift
Answer:
The output power the weightlifter is 2916.67 W.
Explanation:
Given;
weight lifted, W = 700 N
height the weight is lifted, h = 2.5 m
time taken to lift the weight, t = 0.60 s
The output power the weightlifter is calculated as;
Power = Energy applied / time taken
Energy applied = weight lifted x height the weight is lifted
Energy applied = 700 x 2.5
Energy applied = 1750 J
Power = 1750 / 0.6
Power = 2916.67 J/s = 2916.67 W.
Therefore, the output power the weightlifter is 2916.67 W.
Which of the following is most accurate statement about both light and sound wave
Is it true that acceleration occurs when there is a change in speed
Answer:
Acceleration is the rate of change of velocity.
Explanation: For example, acceleration is measured in m/2^2 or meters per second squared. That can also be split up into 2 components. M/s is how speed is measured, and since acceleration is the rate of change of velocity, m/(s*s). You could say that since acceleration is m/s^2, it can also be represented as how much the speed increases over 1 second. if there was an acceleration of 3 m/s^2, the rate of change of speed would be 3m/s every second, meaning that the object would speed up 3m/s every second that passes by.
Hope this helps!
A 20 kg mass is hanging on one side of a pulley and a 5 kg mass is hanging on the other. Determine the acceleration of each mass.
Answer:
i believe it's 7
Explanation:
Which of the following units are the Standard International units for
displacement?
A. Meters (m)
B. Meters per Second (m/s)
C.Meters per Second Squared (m/s2)
D. Seconds per Meter (s/m)
Plz di all plz i will give brainest and thanks to best answer do it right
Why doesn’t the force you exert when sitting on a chair cause the chair to move?
a. The floor exerts a balancing force on the chair.
b. The floor exerts too much force on the chair
c. The floor exerts an unbalancing force on the chair.
d. The floor exerts no force on the chair.
Answer:
the answer is A
Explanation:
What factors affect the amount of potential and kinetic energy a roller coaster has
Answer:
As the roller coaster goes higher, more potential energy is increased in the roller coaster. Caused by gravity and the roller coaster's position, the potential energy is stored in the roller coaster. For example, this ball is at the top of a hill, where potential energy is at it's highest. Potential energy can be calculated by Potential Energy=Mass X Acceleration X Height.
Explanation:
The factor that impact the amount of potential and kinetic energy should be explained below.
Factor impact the amount of energy:Since the roller coaster should be high which there should be more potential energy and the same should be increased.
Due to the gravity and the position of the roller coaster the potential energy should be stored in the rolar coaster.
Just like when the ball is in the top of the hill when there is high potential energy so in this way it should be impacted.
learn more about energy here: https://brainly.com/question/12052751
Which one is an example of a force pushing downward toward the ground.
Group of answer choices
A man pulled weeds in his garden
A woman moved her child from one place to another in a wagon
A bird sat on a telephone wire
A dog tugged on a rope held by a child
Answer: A woman moved her child from one place to another in a wagon
or A bird sat on a telephone wire
Explanation: