Does an object with mass always have momentum?
An object with mass will have momentum. An object which is moving at a constant speed has momentum. An object can be traveling eastward and slowing down; its momentum is westward. Momentum is a conserved quantity; the momentum of an object is never changed.
Can any object have mechanical energy?
Objects have mechanical energy if they are in motion and/or if they are at some position relative to a zero potential energy position (for example, a brick held at a vertical position above the ground or zero height position). A moving car possesses mechanical energy due to its motion (kinetic energy).
Can an object have energy but no momentum explain?
Yes, a body can have energy without possessing momentum.
Can the kinetic energy of a body be negative Class 11?
The kinetic energy of a body cannot be negative because the mass cannot be negative and the square of the speed gives a non-negative number.
What if total energy is negative?
If the total energy is zero or greater, the object escapes. If the total energy is negative, the object cannot escape.
Can total energy ever be negative?
In the zero-energy universe model (“flat” or “Euclidean”), the total amount of energy in the universe is exactly zero: its amount of positive energy in the form of matter is exactly cancelled out by its negative energy in the form of gravity.
Can Exergy be generated?
Exergy is the energy that is available to be used. Energy changes from one form to another (see First Law of Thermodynamics). In contrast, exergy is always destroyed when a process is irreversible, for example loss of heat to the environment (see Second Law of Thermodynamics).
Why is Exergy not conserved?
‘Exergy is not conserved’, while energy of course is conserved by all processes according to the first law of thermodynamics. All transfers of energy imply that exergy is lost because energy is transformed to heat at the temperature of the environment.
What is the difference between energy and exergy?
The main important difference between energy and exergy: energy is conserved, while exergy, a measure of energy quality or work potential, can be consumed.
Which law is used for energy balance?
The exchanges of external work and heat complete the energy balance. That is why the first law of thermodynamics is referred to as the conservation of energy principle, meaning that energy can neither be created nor destroyed, but rather transformed into various forms as the fluid within the control volume changes.
How is Exergy destroyed calculated?
The exergy destruction and entropy generation are related by the expression Exd=T0ΔSgen, where T0 is the reference temperature. If Exd>0 then the process is irreversible; if Exd=0 then the process is reversible; if Exd<0 the process is impossible.