Solids have molecules that move slowly and are close together and are very attracted to eachother.
Liquids have molecules that move freely and are slightly attracted to eachother.
Gases have molecules that move, but aren't attracted to eachother.
There is zero net force required to keep an object moving, even in the same direction. This is because the inertia only depends on the mass of the object moving, not the speed. Therefore, the answer would be none.
Complete Question
A uniform electric field of magnitude 144 kV/m is directed upward in a region of space. A uniform magnetic field of magnitude 0.38 T perpendicular to the electric field also exists in this region. A beam of positively charged particles travels into the region. Determine the speed of the particles at which they will not be deflected by the crossed electric and magnetic fields. (Assume the beam of particles travels perpendicularly to both fields.)
Answer:
The velocity is
Explanation:
From the question we are told that
The magnitude of the electric field is 
The magnetic field is 
The force due to the electric field is mathematically represented as

and
The force due to the magnetic field is mathematically represented as

Now given that it is perpendicular , 
=> 
=> 
Now given that it is not deflected it means that

=> 
=> 
substituting values

