Answer:B,C,D
Explanation:
Thermodynamic efficiency is given by

efficiency can be increased by Keeping
constant and increasing 
Keeping
constant and decreasing
by increasing 
by decreasing
ratio
Answer:
a)48900 metros
b)0.36875 metros
c)75634 metros
d)9.876 metros
Explanation:
Hola, para resolver debemos convertir unidades utilizando equivalencias
a) 48.9 km
1 kilometro = 1000 metros
48.9 x 1000 = 48900 metros
b) 36.875 cm
1 centímetro =0.01 metros
36.875 x 0.01 = 0.36875 metros
c) 756,34 hm
1 hectómetro= 100 metros
756.34 x 100 = 75634 metros
d) 9876 mm
1 milímetro = 0.001 m
9876 x 0.001 = 9.876 metros
I got the 1.0g of coal producves 35,000 joules which is also 8.36 kcals
Answer:
The era of planet formation ended when the remaining hydrogen and helium gas of the solar nebula was swept into interstellar space by the solar winds.
Explanation:
The Solar System is formed from a molecular cloud (compound by gas and dust). If there is a near perturbation to the cloud, maybe due to a supernova explosion, the molecular cloud will collapse under its own gravity. Then, in some point it starts to rotate and will accrete all the material in a disk around the protostar¹.
Inside the disk, dust particles start to collide and accrete until they form planetesimals². As a consequence of the gravitational force of the star, rocky and metallic particles will be more attracted to the inner part of the Solar System (close to the Sun) since they have more mass than gas.
Then, when the star has the necessary pressure and temperature to initiate nuclear reactions in its core, it will be able to emit huge amounts of energy, better known as solar winds. These winds will expel gas (hydrogen and helium) from the Solar System more easily than the rocky and metallic particles.
Notice that when such event occurs, rocky and gaseous planets were already formed.
Key terms:
¹Protostar: A young star.
²Planetesimals: Object formed by many fragments due to the gravitational attraction between them.