1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
OlgaM077 [116]
3 years ago
14

An inventor claims that he wants to build a dam to produce hydroelectric power. He correctly realizes that civilization uses a l

ot more electricity during the day than at night, so he thinks he has stumbled upon a great untapped energy supply. His plan is to install pumps at the bottom of the dam so that he can pump some of the water that flows out from the generators back up into the reservoir using the excess electricity generated at night. He reasons that if he did that, the water would just flow right back down through the generators the next day producing power for free. What is wrong with his plan?
Engineering
1 answer:
Mekhanik [1.2K]3 years ago
6 0

Answer:

The problem is that the pumps would consume more energy than the generators would produce.

Explanation:

Water has a potential energy associated with the height it is at. The higher it is, the higher the potential energy. When water flows down into the turbines that energy is converted to kinetic energy and then into electricity.

A pump uses electricity to add energy to the water to send it to a higher potential energy state.

Ideally no net energy woul be hgenerate or lost, because the generators would release the potential energy and pumps would store it again in the water. However the systems are not ideal, everything has an efficiency and losses. The losses would accumulate and the generator would be generating less energy than the pumps consume, so that system wastes energy.

What should be done is closing the floodgates to keep the water up in the dam at night producing only the power that is needed and releasing more water during the day.

You might be interested in
Engine oil flows at a rate of 1 kg/s through a 5-mmdiameter straight tube. The oil has an inlet temperature of 45°C and it is de
Naily [24]

Answer:

length of tube = 4.12 m

Explanation:

Given data:

flow rate of engine oil = 1 kg/s

diameter of tube = 5-mm

inlet temperature of oil = 45°C

exit temperature of oil = 80°C

surface temperature of tube = 150°C

<u>Determine the required length of the tube </u>

attached below is a detailed solution to the given problem

length of tube = 4.12 m

6 0
3 years ago
What is a type of technology that can be attached to a tag and used to identify postal packages ​
nydimaria [60]
Here’s the answer
Ur welcome

5 0
3 years ago
The project's criteria.
Lena [83]

Answer: design 4

Explanation: I got it right

8 0
2 years ago
A soil weighs 2,520 lbs/CY in its in situ condition, 1,970 lb/CY in its loose condition after excavation, and 3,025 lbs/CY in an
azamat

Answer:

load factor = 0.782

Shrink Factor = 0.833

no of truck is  62500

Explanation:

given data

soil weighs in situ condition  =  2,520 lbs/CY

soil weighs in loose condition  =  1,970 lb/CY

soil weighs in embanked state = 3,025 lbs/CY

average volume = 16 LCY

soil from a borrow pit = 1 million CCY

solution

first we get here Load Factor that is express as

load factor = \frac{1,970}{2550}

load factor = 0.782

and Shrink Factor will be as

Shrink Factor = \frac{2520}{3025}

Shrink Factor = 0.833

and

no of truck will be

no of truck = \frac{1000000}{16}

no of truck is  62500

6 0
4 years ago
Determine the work done by an engine shaft rotating at 2500 rpm delivering an output torque of 4.5 N.m over a period of 30 secon
balu736 [363]

Answer:

work done= 2.12 kJ

Explanation:

Given

N=2500 rpm

T=4.5 N.m

Period ,t= 30 s

torque =\frac{power}{2\pi N}

power=2\pi N\times T

P=2\times \pi \times2500 \times 4.5

P=70,685W

P=70.685 KW

power=\frac{work done}{time}

work done = power * time

                  = 70.685*30=2120.55J

                  = 2.12 kJ

7 0
4 years ago
Other questions:
  • A soil sample has a moist unit weight of 117 pcf, a moisture content of 17 percent, and soil particles with a specific gravity o
    11·1 answer
  • A circular pipe of 25-mm outside diameter is placed in an airstream at 25 °C and 1-atm pressure. The air moves in cross flow ove
    8·1 answer
  • Danny is looking at deploying a new application that requires root-level access to the server. He is currently researching the c
    13·1 answer
  • Lithium at 20°C is BCC and has a lattice constant of 0.35092 nm. Calculate a value for the atomic radius of a lithium atom in na
    8·1 answer
  • What is the angle of the input
    12·1 answer
  • WHAT IS MEANT BY BJT AND FUNCTION OF BJT
    8·1 answer
  • Lois is in high school and enjoys studying math and science subjects. She aspires to get into the robotics industry after comple
    8·1 answer
  • According to the rules of dimensioning, how should the written notes appear?
    8·1 answer
  • 1) Plastics that soften when heated,harden when cooled, and then can be heated and softened many times
    6·1 answer
  • A particle moving on a straight line has acceleration a = 5-3t, and its velocity is 7 at time t = 2. If s(t) is the distance fro
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!