C. Maintain correct Posture
1. First blank is A. Conductors
Second blank is D. Insulators
2. C. Heat
Answer:
1.503 J
Explanation:
Work done in stretching a spring = 1/2ke²
W = 1/2ke²........................... Equation 1
Where W = work done, k = spring constant, e = extension.
Given: k = 26 N/m, e = (0.22+0.12), = 0.34 m.
Substitute into equation 1
W = 1/2(26)(0.34²)
W = 13(0.1156)
W = 1.503 J.
Hence the work done to stretch it an additional 0.12 m = 1.503 J
Semantically? An electric field does not have to be static while in electrostatics it's generally assumed that the electric field does not change or only changes so slowly that its rate of change doesn't matter. That's very different in electrodynamics where electric and magnetic field changes are always coupled.
