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
jok3333 [9.3K]
3 years ago
14

A power station burns 75 kilograms of coal per second. Each kg of coal contains 27 million joules of energy.

Physics
2 answers:
weqwewe [10]3 years ago
5 0

Answer:

jj

Explanation:

Energy obtained by burning of 1 kg coal = 27 million Joule

a.

Energy obtained by burning of 75 kg coal = 27 x 75 = 2025 million Joule

Power = Energy obtained per second

Power = \frac{2025}{1} million Joule per second

P = \frac{2025}{1}\times 10^{6} Watt

P = \frac{2.025}{1}\times 10^{9} Watt

b.

Input power =  2025 million Watt

Output power = 800 million Watt

Efficiency = output power / input power

Efficiency = 800 / 2025 = 0.395

Efficiency = 39.5%

olasank [31]3 years ago
4 0
A) P = 75 \times (2.7\times10^7) = 2.025\times10^9 W

b) Efficiency =  \frac{8\times10^8}{2.025\times10^9} \times 100 \approx 39.5\%
You might be interested in
A piece of warm concrete is placed in a cold-water tank, and energy flows between the concrete and the water. Which way does the
sammy [17]

Answer:

Heat flows from hot to cold objects. When a hot and a cold body are in thermal contact, they exchange heat energy until they reach thermal equilibrium, with the hot body cooling down and the cold body warming up. This is a natural phenomenon we experience all the time.

Explanation:

3 0
2 years ago
A 50 g mass is freely hanging from a horizontal meter stick at a distance of 99 cm from the pivot. Calculate the weight force W
Neko [114]

Answer:

W = 0.49 N

τ = 0.4851 Nm

Force

Explanation:

The weight force can be found as:

W = mg

W = (0.05 kg)(9.8 m/s²)

<u>W = 0.49 N</u>

The torque about the pivot can be found as:

τ = W*d

where,

τ = torque

d = distance between weight and pivot = 99 cm = 0.99 m

Therefore,

τ = (0.49 N)(0.99 m)

<u>τ = 0.4851 Nm</u>

The pivot exerts a  <u>FORCE </u>on the meter stick because the pivot applies force normally over the stick and has a zero distance from stick.

6 0
3 years ago
What is the polarization ice cap how long is yes
lubasha [3.4K]

Answer:

What???

Explanation:

5 0
3 years ago
Explain how wavelength and frequency are important in determining the type of light.
asambeis [7]
It is important to note that the electromagnetic spectrum has a variety of wavelength and frequency of light in it. Some lights we can see, while others are not visual to our naked eye. It is actually very important to determine the kind of light as different lights have different wavelengths and frequencies. some lights are of very high frequency like the gamma rays, while others are of far lower frequency. <span />
7 0
3 years ago
I drop a meter stick , and catch it as it falls. If it fell exactly 22 cm, how much did it take me to catch the meter stick (wha
statuscvo [17]
D=Vot+1/2at^2

In this case, there is no initial y velocity so the term Vot=0 so d=1/2at^2

acceleration=acceleration due to gravity=-9.8m/s^2

It falls - 22cm or -0.22m

We have - 0.22=1/2(-9.8)t^2

t^2=(-0.44)/(-9.8)

t=sqrt[0.44/9.8]
3 0
3 years ago
Other questions:
  • How long does it take lewis hamilton travelling at 156 mph to cover 16 miles?
    11·1 answer
  • Suppose our experimenter repeats his experiment on a planet more massive than Earth, where the acceleration due to gravity is g
    13·1 answer
  • A small piece of dust of mass m = 4.1 µg travels through an electric air cleaner in which the electric field is 466 N/C. The ele
    6·1 answer
  • What type of lens does our eye function as, and what is it's purpose?
    11·2 answers
  • If this were a theoretical frictionless plane, what would be the mechanical advantage?
    12·1 answer
  • When dry ice appears to be smoking what is actually happening
    6·1 answer
  • In downtown Chicago, the east-west blocks are 400 ft long while the north-south blocks are 280 ft long. Because of the many one-
    12·1 answer
  • A bodybis thrown vertically upward with velocity of 30m/s calculate the the maximum height attained​
    9·2 answers
  • I desperately need help with my Physics Exam I am failing this class will mark Brainliest to whoever helps the most: PART 1 (I d
    9·1 answer
  • A golf ball is hit so that it leaves the club face at a velocity of 45m/s at an angle of 40° to the horizontal. by ignoring the
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!