I think B is the most correct, because logically it's harder to bend a stiffer spring than it is to bend a softer one. Also, I don't think length comes into play. So B.
= Heat released to cold reservoir
= Heat released to hot reservoir
= maximum amount of work
= temperature of cold reservoir
= temperature of hot reservoir
we know that

eq-1
maximum work is given as
=
- 
using eq-1
=
- 
Answer:

Explanation:
Here we know that the EMF induced in this Field is given as

here B = perpendicular component of magnetic field
v = speed of the bird
L = length of the wings
now we have



now we have


Answer:
10 kJ
Explanation:
W = Fd
W = (μN)(vt)
W = μ(mg)vt
W = 0.7(42.9)(9.81)(9)(3.8)
W = 10,075.12506 J
W ≈ 10 kJ
Your answer would be true. Because if we didn't have those pieces of evidence, we wouldn't know about a lot of the ancient civilizations that we know today without that. Small pieces of evidence like that can help us to determine how they lived, or what they used to do, or even what they ate.