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
gayaneshka [121]
3 years ago
10

An engine has a hot-reservoir temperature of 980 K and a cold-reservoir temperature of 570 K. The engine operates at three-fifth

s maximum efficiency. What is the efficiency of the engine?
Physics
2 answers:
hram777 [196]3 years ago
7 0

Answer:

efficiency of engine is 0.21

Explanation:

given:

Th=980 K

Tc=570 K

since efficiency of engine is given as:

n=3/5*n_m

 =3/5(1-Tc/Th)

 =0.21

efficiency of engine is 0.21

pshichka [43]3 years ago
4 0

Answer:

E = 0.251 or 25.1%

The efficiency of the engine is 0.251 or 25.1%

Explanation:

Maximum Efficiency of an engine can be expressed as;

Em = workdone/heat energy supplied

Em = 1 - Qc/Qh = 1 - Tc/Th

Given;

Tc = cold temperature = 570K

Th = hot temperature = 980K

Substituting the values;

Em = 1 - 570/980

Em = 0.4184

But the engine operates at three-fifths the maximum efficiency

E = 3/5 × Em

Substituting Em

E = 3/5 × 0.4184

E = 0.251 or 25.1%

The efficiency of the engine is 0.251 or 25.1%

You might be interested in
Hello everyone.Roads are made winding in hilly regions why?Explain​
kicyunya [14]

Answer:

Because winding roads have a gentle slope on hills, so it's easy to climb it than a steepy.

3 0
2 years ago
What is the name and symbol of the element in the second row and fourteenth column of the periodic table? Hint: Review your peri
Papessa [141]
The answer is Carbon. Beyond being the only element listed here that is located in the second row, it is also in the fourteenth column of the table if you count from left to right. Hope this helps!
4 0
3 years ago
I WILL GIVE BRAINLIEST
11111nata11111 [884]

Answer:

A, B, F

Explanation:

I believe these are the answers, sorry if it is incorrect.

3 0
3 years ago
Estimated speed of the vehicle
SSSSS [86.1K]

Really, Gundy ? ! ?

The formula for the car's speed is given and discussed in the box.  The formula is

v = √(2·g·μ·d)

Then they <em>tell</em> you that μ is 0.750 , and then they <em>tell</em> you that d = 52.9 m .  Also, everybody knows that 'g' is gravity = 9.8 m/s² .

They also tell us that the mass of the car is 1,000 kg, and they tell us that it took 3.8 seconds to skid to a stop.  But we already <em>have</em> all the numbers in the formula <em>without</em> knowing the car's mass or how long it took to stop.  The police don't need to weigh the car, and nobody was there to measure how long the car took to stop.  All they need is the length of the skid mark, which they can measure, and they'll know how fast the guy was going when he hit the brakes !

Now, can you take the numbers and plug them into the formula ? ! ?

v = √(2·g·μ·d)

v = √( 2 · 9.8 m/s² · 0.75 · 52.9 m)

v = √( 777.63 m²/s²)

v = 27.886 m/s

Rounded to 3 digits, that's  <em>27.9 m/s </em>.

That's about 62.4 mile/hour .



3 0
3 years ago
How far will 20 N of force stretch a spring with a spring constant of 140 N/m?
densk [106]

Answer:

0.143 m

Explanation:

The relationship between force applied on a string and stretching of the spring is given by Hooke's law:

F=kx

where

F is the force exerted on the spring

k is the spring constant of the spring

x is the stretching of the spring from its equilibrium position

In this problem, we have:

F = 20 N is the force applied on the spring

k = 140 N/m is the spring constant

Solving for x, we find how far the spring will stretch:

x=\frac{F}{k}=\frac{20}{140}=0.143 m

7 0
3 years ago
Other questions:
  • It has been argued that power plants should make use of off-peak hours to generate mechanical energy and store it until it is ne
    11·1 answer
  • PLZ HELP ME ASAP 30 POINTS
    6·1 answer
  • What's the hikers average velocity during part D of the hike?
    7·1 answer
  • HNO3 (aq) + H20 (1) ► NO3- (aq) + H30+ (aq)
    6·1 answer
  • The human body can store excess animo acids as a protein source ?
    12·1 answer
  • A 5.50 kg crate is suspended from the end of a short vertical rope of negligible mass. An upward force F(t) is applied to the en
    10·1 answer
  • If my candle has a brightness of 15 candela from a distance of 2 meter. What would the brightness be at a distance of 6 meters?
    13·1 answer
  • B)
    15·1 answer
  • How do make friends and other people like being around u also im lonely
    5·2 answers
  • A transverse mechanical wave is traveling along a string lying along the x-axis. The displacement of the string as a function of
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!