The electric currents induces a magnetic field. They changing magnetic field can be induce an electric current.
Seriously... B the other options are rediculous
Answer: They will fall at the same time
Explanation:I had a google doc about this
Answer:
Energy needed = 54.02 J
Explanation:
the Energy in an elastic spring from hookes law is given as
F= ke , therefore the energy (E) is
E = 
K = 19.5 N/cm
e = 1.39cm
E =
x 19.5 x 1.39
E = 13.55 J
The energy to stretch the spring for 6.93cm is
E =
x 19.5 x 6.93
E = 67.57 J
The more energy needed for the further stretch is
67.57 - 13.55
Energy needed = 54.02 J
The right answer is D, the aplitude of summaric wave.