Simply be used as a reference point <span>to describe its position. a fact forming the basis of an evaluation or assessment; criterion. They had few cultural </span>reference points<span> in common.</span>
A substance with LOW pH. The lower the pH, the higher the acidity level is. pH has a direct effect on how acidic a substance is. For an example, battery acid. Battery acid has a pH level of about 1. This means that battery acid is very acidic. A substance is concidered acidic when it dips below the neutral pH level of 7.
Answer:
Explanation:
The distance of Earth from the Sun is 
and of Mars from the Sun is 
. Let assume that both planets have circular orbits. The centripetal accelaration can be found by using the following expression:
Since planet has translation at constant speed, this formula is applied to compute corresponding speeds:
Earth:
Mars:
Now, centripetal accelarations can be found:
Earth:
Mars:
The ratio of Earth's centripetal acceleration to Mars's centripetal acceleration is:
Answer:
Explanation:
First last of thermodynamics, just discusses the changes that a system is undergoing and the processes involved in it. It explains conservation of energy for a system undergoing changes or processes.
Second law of thermodynamics helps in defining the process and also the direction of the processes. It tells about the possibility of a process or the restriction of a process. It states that the entropy of a system always increases.
For this to occur the energy contained by a body has to diminish without converting to work or internal energy. So imagine a machine which works with less than efficiency, this means there are losses but they don’t show up anywhere. But the energy is obtained from a higher energy source to lower.
The easy way to do this is with an imaginary device that extracts zero-point energy to heat a quantity of gas. Energy is being created, so the first law is violated, and the entropy of the system is increasing as the gas heats up.
First law is violated since the energy conversion don't apply but the direction of work is applied so second law is satisfied.
Answer: c) 90 m/s
Explanation:
Given
Invest velocity, v1 = 250 m/s
Inlet specific enthalpy, h1 = 270.11 kJ/kg = 270110 J/kg
Outlet specific enthalpy, h2 = 297.31 kJ/kg = 297310 J/kg
Outlet velocity, v2 = ?
0 = Q(cv) - W(cv) + m[(h1 - h2) + 1/2(v1² - v2²) + g(z1 - z2)]
0 = Q(cv) + m[(h1 - h2) + 1/2(v1² - v2²)]
0 = [(h1 - h2) + 1/2(v1² - v2²)]
Substituting the values of the above, we get
0 = [(270110 - 297310) + 1/2 ( 250² - v²)
0 = [-27200 + 1/2 (62500 - v²)]
27200 = 1/2 (62500 - v²)
54400 = 62500 - v²
v² = 62500 - 54400
v² = 8100
v = √8100
v = 90 m/s
