Answer : The kinetic energy depends directly on the mass of a particle.
Explanation :
We know that the kinetic energy of any particle is given by :

Where,
m is the mass of an object.
v is the velocity with which it is moving
Kinetic energy is due to the motion of the particle.
So, the kinetic energy of a particle is directly proportional to its mass.
Hence, the conclusion of the question is if the mass of a particle is increases then its kinetic energy also increase.
Answer:
The z-component of the force is
Explanation:
From the question we are told that
The charge on the particle is
The magnitude of the magnetic field is 
The velocity of the particle toward the x-direction is 
The velocity of the particle toward the y-direction is

The velocity of the particle toward the z-direction is

Generally the force on this particle is mathematically represented as

So we have

substituting values
So the z-component of the force is
Note : The cross-multiplication template of unit vectors is shown on the first uploaded image ( From Wikibooks ).
1) 15 / 12 = 1.25 ratio
2) to increase acceleration 1.25 times (with same F, or same engine) you have to lower mass 1.25 times
3) 1515/1.25 = 1212 kg
choose A
'Pressure' is (force) / (area).
The only choice with those units is #1 .