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
WITCHER [35]
3 years ago
8

A river flowing steadily at a rate of 175 m3/s is considered for hydroelectric power generation. It is determined that a dam can

be built to collect water and release it from an elevation difference of 80 m to generate power. Determine how much power can be generated from this river water after the dam is filled.
Physics
1 answer:
Alex_Xolod [135]3 years ago
6 0

Answer:

137200000 watts or 137200 kilowatts

Explanation:

The formula for power is P= dhrg

Where P = Power in watts

d = density of water (1000 kg/m^3)

h = height in meters

r = flow rate in cubic meters per second,

g = acceleration due to gravity of 9.8 m/s^2,

Plugging in the known values,

we get

P = 1000 kg/m^3 * 80 m * 175 m^3/s * 9.8 m/s^2

P = 80000 kg/m^2 * 175 m^3/s * 9.8 m/s^2

P = 14000000 kg m/s * 9.8 m/s^2

P = 137200000 kg m^2/s^3

P = 137200000 watts or 137200 kilowatts

The above figure assumes 100% efficiency which is impossible. A good efficiency would be 90% so the actual power available would be close to 0.90 * 137200 = 123480 kilowatts

You might be interested in
A car travels 40 miles in 30 minutes.
lukranit [14]

Answer:

(a)Average velocity ,v =128.74 Km/hr

(b)Kinetic Energy , K=958546.875 Joule

(c)Distance, s=268.8m

(d)Acceleration, a= - 2.38 m/s^2

<u>Explanation</u>:

<u>Given</u>:

Distance travelled = 40 miles

Time taken = 30 minutes.

(A) The average velocity in kilometres/hour

Converting 40 miles into km ,

we know that,

1 mile = 1.60934

40 miles =  40 x 1.60934

so 40 miles  =  64.3738 Km

similarly converting 30 minutes into hours

1 minute = \frac{1}{60}hours

30 minute = \frac{30}{60}hours

30 minute = \frac{1}{2}hours

Now

Average velocity = \frac{Speed}{time}

Substituting Values,

Average velocity = \frac{64.3738}{\frac[1}{2}}

Average velocity = 64.3738 \times 2

Average velocity =128.74 Km/hr

(B) If the car weighs 1.5 tons, what is its If the car weighs 1.5 tons, what is its kinetic energy in joules (Note: you will need to convert your velocity to m/s)? in joules (Note: you will need to convert your velocity to m/s)?

Converting 1.5 tons into kg we get

1 ton = 1000 kg

so 1.5 ton =1500 kg

converting  velocity to m/s

128.74  \times \frac{5}{18}

=>35.75 m/s----------------------------------------------------------(1)

kinetic energy  K= \frac{1}{2}mv^2

Substituting the values,

K= \frac{1}{2}1500(35.75)^2

K= \frac{1}{2}1500(1278.06)

K= \frac{1500 \times (1278.06)}{2}

K= \frac{1917093.75}{2}

K=958546.875 Joule---------------------------------------------(2)

(c)When the driver applies the brake, it takes 15 seconds to stop. How far does the car travel (in meters) while stopping

Lets use Distance formula,

S= ut+\frac{1}{2}at^2

Substituting the known values,

s= ut+\frac{1}{2}at^2

s= (37.75)(15)+\frac{1}{2}a(15)^2

s=566.25+\frac{1}{2}a(225)

s=566.25+\frac{(225a)}{2}-------------------------------------(3)

(D) What is the average acceleration of the car (in m/s2) during braking?

Using the formula

v=u +at

re arranging the formula we get,

a = \frac{v - u}{t}

Substituting the values

a = \frac{0 - 35.75}{15}

a = \frac{- 35.75}{15}

a= - 2.38 m/s^2----------------------------------------(4)

Now substituting 4 in 3 we get

s=566.25+\frac{(225( - 2.38)}{2}

s=566.25+\frac{-535.5}{2}

s=536.25-267.75

s=268.8m--------------------------------------------------------------(5)

4 0
3 years ago
Select the best reason for studying the past and its effect on us today based on "The Terror of the Middle Ages." A. to learn wh
JulijaS [17]

it is D for sure im good with history

4 0
2 years ago
Read 2 more answers
An elite tour de france cyclist can maintain an output of 420 watts during a sustained climb. at this output power, how long wou
julia-pushkina [17]
<span>2002 seconds, or 33 minutes, 22 seconds. First, let's calculate how many joules it will take to lift 78 kg against gravity for 1100 meters. So: 78 kg * 9.8 m/s^2 * 1100 m = 840840 kg*m^2/s^2 Now a watt is defined as kg*m^2/s^3, so a division of the required joules should give us a convenient value of seconds. So: 840840 kg*m^2/s^2 / 420 kg*m^2/s^3 = 2002 seconds. And 2002 seconds is the same as 33 minutes, 22 seconds.</span>
7 0
3 years ago
If a car is traveling at an average speed of 60 kilometers per hour how long does it take to travel 12 kilometers
lara31 [8.8K]

Answer:

The time taken to travel is, t = 12 minutes

Explanation:

Given data,

The speed of the car, v = 60 km/h

The distance of travel, d = 12 km

The time taken for the travel is t = ?

The speed is defined as the distance divided by the time taken to travel. The formula for speed is,

                                  v = d/t

∴                                  t = d/v

                                    t = 12 km / 60 km/h

                                    t = 0.2 h

                                     t = 12 minutes

Hence, the time taken to travel is, t = 12 minutes.

5 0
3 years ago
Which of the following is true?
lesantik [10]

Answer:

D

Explanation:

What it means to be an autotroph is that you make your own food and plants do that by photosynthesis to be a heterotroph is finding food from other sources like autotrophs or even other heterotrophs

3 0
3 years ago
Read 2 more answers
Other questions:
  • List three ways you can use an electric current describe the energy change that takes place
    15·1 answer
  • An older-model car accelerates from 0 to speed v in a time interval of δt. a newer, more powerful sports car accelerates from 0
    13·1 answer
  • A charge of 8.4 × 10–4 C moves at an angle of 35° to a magnetic field that has a field strength of 6.7 × 10–3 T.
    11·1 answer
  • A hypodermic needle consists of a plunger of circular cross-section that slides inside a hollow cylindrical syringe. when the pl
    6·1 answer
  • Heating food under a heat lamp is an example of heat transfer by
    7·1 answer
  • What is the energy level of hydrogen?
    10·1 answer
  • A 49.5-turn circular coil of radius 5.10 cm can be oriented in any direction in a uniform magnetic field having a magnitude of 0
    15·1 answer
  • A ball is kicked at 10.4 m/s at an angle of 32 degrees to the horizontal
    14·1 answer
  • How is cell division different for a unicellular organism than it is for a cell in a multicellular organism?
    11·1 answer
  • Two loudspeakers emit sound waves of the same frequency along the x-axis. The amplitude of each wave is a. The sound intensity i
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!