The heat taken to do the 10,000 J of work is 4081 J
<u>Explanation:</u>
The ratio of the temperature difference between the reservoirs and the temperature of the hot reservoir is termed as maximum thermal efficiency.
Maximum thermal efficiency is
1 - (Tc / Th).
where Tc represents the absolute temperature of the cold reservoir
Th represents the absolute temperature of the hot reservoir.
1 - (293/495) = 0.408
If the input is 10,000 J, then 4081 J is used to do work. The remaining 5919 J is rejected as heat into the air.
Explanation:
B. More mass results in less acceleration.
Answer:
&
Explanation:
Given:
- interior temperature of box,
- height of the walls of box,
- thickness of each layer of bi-layered plywood,
- thermal conductivity of plywood,
- thickness of sandwiched Styrofoam,
- thermal conductivity of Styrofoam,
- exterior temperature,
<u>From the Fourier's law of conduction:</u>
....................................(1)
<u>Now calculating the equivalent thermal resistance for conductivity using electrical analogy:</u>
.....................(2)
Putting the value from (2) into (1):
is the heat per unit area of the wall.
The heat flux remains constant because the area is constant.
<u>For plywood-Styrofoam interface from inside:</u>
&<u>For Styrofoam-plywood interface from inside:</u>
Power = work/time
= 500/10
= 50J/s or 50 watt