Answer:
The change in energy of the gas during the process is 
joules.
Explanation:
We can represent this process by the First Law of Thermodynamics, in which gas does work on its surroundings and absorbs heat from there to describe its change in energy. In other words:
Where:
- Heat absorbed by the gas, measured in joules.
- Work done by the gas, measured in joules.
- Change in energy, measured in joules.
If we know that 
and 
, the change in energy of the gas is:
The change in energy of the gas during the process is joules.
Answer:
C. The voltage drop across the resistor is 2.1V and nothing about the current through the resistor.
Explanation:
When connected in parallel, voltage across the resistances are the same. So if 2.1V was dropped across the LED then 2.1V was also dropped across the resistor. However, this tells us nothing about the current through the resistor. We can find the current across the resistor if we know the resistance of the resistor, but that's about it.
If it were a series connection, then the current would have been the same, but the voltage drop were another story.
Gravitational acceleration, g = GM/r^2. Additionally, for a satellite in a circular orbit, g = v^2/r
Where, G = Gravitational constant, M = Mass of earth, r = distance from the center of the earth to the satellite, v = linear speed of the satellite.
Equating the two expressions;
v^2/r = GM/r^2
v = Sqrt (GM/r);
But GM = Constant = 398600.5 km^3/sec^2
r = Altitude+Radius of the earth = 159+6371 = 6530 km
Substituting;
v = Sqrt (398600.5/6530) = 7.81 km/sec = 781 m/s
Reflection from such a rough surface is called diffuse reflection and appears matte
Gravitational forces are forces of attraction. It's like the Earth pulling on you and keeping you on the ground.
