I’m confused but I will answer that small snippet of a question, and it is that nobody knows how many black holes are in space but scientist have estimated that there are 10 million to a billion black holes
1: a machine makes our work easier
2: a machine can help us find important information
3: a machine can help us transport from a place to another
The rate of a reaction increases if the temperature is increased. The concentration of a dissolved reactant is increased. The pressure of a reacting gas is increased.
In step 1, to increase the potential energy, the iron will move towards the electromagnet.
In step 2, to increase the potential energy, the iron will move towards the electromagnet.
<h3>Potential energy of a system of magnetic dipole</h3>
The potential energy of a system of dipole depends on the orientation of the dipole in the magnetic field.

where;
is the dipole moment- B is the magnetic field


Increase in the distance (r) reduces the potential energy. Thus, we can conclude the following;
- In step 1, to increase the potential energy, the iron will move towards the electromagnet.
- In step 2, when the iron is rotated 180, it will still maintain the original position, to increase the potential energy, the iron will move towards the electromagnet.
Learn more about potential energy in magnetic field here: brainly.com/question/14383738
Divide the distance by the speed:
(18 m) / (42 m/s) = 3/7 s ≈ 0.43 s