Answer:
If the starting and ending points are identical, the overall work equals zero.
Explanation:
Option (D) is correct.
A force is considered conservative when the work performed by it while moving an object from point A to point B does not rely on the path taken and remains consistent across all paths. The work done is determined solely by the initial and final locations of the particle. Thus, when the initial and final positions in a conservative field coincide, the work is said to be zero.
Response:
The intensity of light 18 feet underwater is about 0.02%
Clarification:
Employing Lambert's law
Let dI / dt = kI, where k is a proportionality factor, I represents the intensity of incident light, and t indicates the thickness of the medium
Then dI / I = kdt
Taking logarithms,
ln(I) = kt + ln C
I = Ce^kt
At t=0, I=I(0) implies C=I(0)
I = I(0)e^kt
At t=3 & I=0.25I(0), we find 0.25=e^3k
Solving for k gives k = ln(0.25)/3
k = -1.386/3
k = -0.4621
I = I(0)e^(-0.4621t)
I(18) = I(0)e^(-0.4621*18)
I(18) = 0.00024413I(0)
The intensity of light 18 feet underwater is about 0.2%
