Answer:
114.44 J
Explanation:
From Hook's Law,
F = ke................. Equation 1
Where F = Force required to stretch the spring, k = spring constant, e = extension.
make k the subject of the equation
k = F/e.............. Equation 2
Given: F = 10 lb = (10×4.45) N = 44.5 N, e = 4 in = (4×0.254) = 1.016 m.
Substitute into equation 2
k = 44.5/1.016
k = 43.799 N/m
Work done in stretching the 9 in beyond its natural length
W = 1/2ke²................. Equation 3
Given: e = 9 in = (9×0.254) = 2.286 m, k = 43.799 N/m
Substitute into equation 3
W = 1/2×43.799×2.286²
W = 114.44 J
Explanation:
Trees, because of their height, are natural lightning rods. Electricity seeks the path of least resistance, and the moisture inside a tree is a much better conductor than air. This means a tree provides the preferred path for lightning to reach the ground.
I think the correct answer from the choices listed above is option B. A parallel circuit differ from a series circuit in a sense that a <span>series circuit has one path for electrons, but a parallel circuit has more than one path. In a parallel circuit there two or more paths for current to flow while a series circuit only has one.</span>