I think that the mobile home would have the lowest maintenance cost. But it all depends. You didn't give the information on where do the housing options take place so the cost may vary.
When an object is placed on the opposite end of a lever and the near end is held in place without being allowed to move upwards, the lever has potential energy.
We know that:
f * λ = c
<span>and
E = h*f
so,rearranging:
</span>
<span>E/h = C/λ
given:
h = </span><span>6.90 × 10^2 nm
</span><span>substituting the values:
E = </span> C/λ<span> x h
(c is the speed of light;that is 3x10^8 m/s)
</span> = 3x10^8 x 6.626x10^-34 / 6.90 x10^7m x 6.022x10^23
Hence,
using calculator:
we get,
E = 1.69 x 10^5 Joules