The park has added two more cars to the already existing roller coaster. If the park wants to maintain the speed of the roller coaster with the addition of the cars, what must it do? A) Increase the height a point A. B) Increase the heights at point A and B. C) Reduce the number of hills and dips in the course. D) Increase the friction between the wheels and the track.

Answer:

Hello! the efficiency of a thermal engine depends on how much of the initial input is transformed into work, Here 270°c is the input and 210°c is the output.

Then the efficiency is calculated as e = 1 - Tc/Th, where Th is the hot temperature (in this case 270°C) and Tc is the cold temperature (in this case 210°C)

First we need to write the temperatures in kelvin degrees, this can be done by adding 273.15 to the celsius scale:

Th = 270 + 273.15 = 543.15

Tc = 210 +273.15 = 483.15

then the efficiency is e = 1 - 543.15/483.15 = 0.11

if we write this as a percentage, we get an efficiency of 11%, then the fourth answer is the correct one.

Answer:

Given:

Th = 270 °C = 270+273 = 543 K, hot temperature

Tc = 210 °C = 210+273 = 363 K, cold temperature

According to the Carnot theorem, the maximum efficiency achievable by a heat engine between a hot and cold temperature is

η = 1 - Tc/Th

  = 1 - 363/543

  = 0.668 = 11.047 (approx)

Answer:  11.0%  (nearest integer)

Answer:

Atom X will accept electrons from atom Y

Explanation:

The outermost shell of an atom is full when it contains 8 valence electrons (except for the first shell, which only contains 2 electrons). Therefore, any atom tends to accept electrons if it's very close to complete the shell with 8 electrons, or to donate electrons if it has only a few electrons in its outest shell.

In this case, we have:

- Atom X: 6 valence electrons --> it tends to accept electrons, since it needs only 2 of them to complete the shell

- Atom Y: 2 valence electrons --> it tends to donate electrons, so it has its outermost shell completed also

- Atom Z: 8 valence electrons --> it has no tendency in donate/accept electrons, since its outermost shell is already full

Therefore, atom Y will donate its 2 valence electrons to atom X, so that both of them have their outermost shell completed.

Answer:

Atom X will accept electrons from atom Y

Explanation:

I did the test

one atom of calcium, one atom of carbon, and three atoms of oxygen

CaCO3

(sorry if this is not what you are looking for)

I believe it is angles