The correct answer would be the first option. The process that would need more energy would be vaporizing 1 kg of saturated liquid water at a pressure of 1 atmosphere. This can be seen from the latent heat of vaporization of each system. For the saturated water at 1 atm, the latent heat is equal to 40.7 kJ per mole while, at 8 atm, the latent heat is equal to 36.4 kJ per mole. The latent heat of vaporization is the amount of heat needed in order to vaporize a specific amount of substance without any change in the temperature. As we can observe, more energy is needed by the liquid water at 1 atm.
Answer:
Efficiency of a machine is how well the machine works and what the machine is capable of doing.
Mechanical advantage=Load/Effort.
720/180=4
The change in potential energy of an object is given by
where
m is the mass of the object
g is the gravitational acceleration
is the increase in altitude of the object
In our problem,
is the mass of the book,
and
is the increase in altitude of the book, so its variation of potential energy is
