-- First, it can never swing to a higher elevation off the floor
than where it was when she let it go. The higher it is off the
floor, the more potential energy it has, and that's all the energy
she gave it when she lifted it to the height of her chin.
-- Second, it can't even return to THAT height, because during
its swing out and back, it's losing energy by plowing through air.
So each swing is slightly narrower, and ends slightly lower, than
the one before it.
Answer:
The correct option is;
Why car engines are not perfectly efficient
Explanation:
The Second Law of Thermodynamics states that the total entropy, S, of a system combined with the entropy of its surrounding cannot be decreased, such that for an irreversible process, the entropy always increases and > , while for a reversible process the entropy is constant and
The entropy is a measure of the amount of useful work obtainable from heat (or thermal) energy
A system with a low entropy has high amounts of heat energy capable of doing work while a high entropy system can produce only a small amount of useful work from the available thermal energy
In car engines, as the parts start to move, the entropy of the system increases alongside the generated heat lost to the environment, the amount of heat available for doing work reduces and therefore, the entropy increases further and the ratio of work obtainable from a given input of heat energy reduces and therefore, the car engine is not perfectly efficient.
Kinetic Energy = 1/2mv^2
The solution is attached below.
Answer:
B temperature is an indirect measurement of the heat energy in a substance
Explanation:
The concept of temperature can be easily understood by looking at what happens when two objects are placed in contact with each other. By common experience, we know that the hotter object transfers heat energy to the colder object, until the two objects are in thermal equilibrium (= they have same temperature).
Thinking about the example above, we can say therefore that the temperature is an indirect measurement of the heat energy possessed by an object (or substance).
For a monoatomic gas, for instance, we define its internal energy as
where n is the number of moles, R is the gas constant, and T is the absolute temperature. From the formula, we see that the temperature is related to the internal energy of the gas, so measuring the temperature means indirectly measuring its internal energy.