By adding a vibration at the natural frequency of the medium-A
I think it is option (C).
If the answer is helpful then mark me as brainly.
Answer:
(1) The orbits are ellipses, with focal points ƒ1 and ƒ2 for the first planet and ƒ1 and ƒ3 for the second planet. The Sun is placed in focal point ƒ1.
(2) The two shaded sectors A1 and A2 have the same surface area and the time for planet 1 to cover segment A1 is equal to the time to cover segment A2.
(3) The total orbit times for planet 1 and planet 2 have a ratio a13/2 : a23/2
The closer together they are the harder it is to hold on to because the magnetic field is stronger as it gets closer.
Answer:
D. The electromagnet's magnetic field is stronger close to it than far from it.
This is the answer for ur question
