<span>In my opinion, I myself believe that there are only two supernovae. The first is the white dwarf. It makes sense because if something is too big for its size, it will "explode". Just like a basketball with too much air. Massive star supernovae is like something has reached it's full potential and cannot get any bigger or better.</span>
Momentum is conserved after the collision
Momentum of 2 Kg before collision = 2 * 3 = 6
Momentum of 4 kg before collision = 4 * -3 = -12
so 6 + -12 = 2 * -4 + 4 *x where x is velocity of 4kg marble.
4x - 8 = -6
4x = 2
x = 0.5
Velocity of 4 kg marble is 0.5 m/s after collision
The 2 kg marble will move in the opposite direction to which it was moving before the collision.
Answer:

Explanation:
The resistance of a conductor is directly proportional to its length and is inversely proportional to its cross-sectional area, this dependence is given by:

is the material's resistance, L is the legth and A is the cross-sectional area.
For the first and second coils, we have:

For the third and fourth coils, we have:

I think this is the answer hope it helps