Gauss’s law of magnetism states that the net magnetic flux through any closed surface is zero.
a. true
b. false

True

Explanation:

Gauss's law:

It is one of the Maxwell's equations which are the foundation of Electrodynamics. According to this law magnetic field has zero divergence and magnetic monopole can't exist. Inside a closed surface, the magnetic flux inward at the south pole will be exactly equal to the outward magnetic flux at the north pole of the magnetic dipole. Thus, the net magnetic flux will be zero.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

read more on -

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it