Answer:
The power output of this engine is 
The the maximum (Carnot) efficiency is 
The actual efficiency of this engine is 
Explanation:
From the question we are told that
The temperature of the hot reservoir is 
The temperature of the cold reservoir is 
The energy absorbed from the hot reservoir is 
The energy exhausts into cold reservoir is 
The power output is mathematically represented as

Where t is the time taken which we will assume to be 1 hour = 3600 s
W is the workdone which is mathematically represented as

substituting values

So


The Carnot efficiency is mathematically represented as



The actual efficiency is mathematically represented as

substituting values


Answer: Radiation
Explanation: Radiation is the energy that comes from a source in form of electromagnetic waves, subatomic particles, light, or heat which travels through space.
Examples of radiation include the light, heat, and particles emitted from the Sun.
Using a foil barrier to prevent heat transfer is possible because foil has a silver color, and silver reflects light and heat instead of absorbing them. This is the opposite of black surfaces that absorb heat.
So in homes where these foil reflective barriers are used, the transfer of heat through Radiation is highly reduced.
The amount of heat needed to increase the temperature of a substance by

is given by

where
m is the mass of the substance

the specific heat capacity

the increase in temperature
In our problem, the mass of the water is m=750 g, the specific heat is

and the amount of heat supplied is

, so if we re-arrange the previous formula we find the increase in temperature of the water:
If <em>the isotherms</em> are spaced closely together over some portion of the map, there is a drastic temperature change over that portion.