That statement is as false as false can be.
Roughly 78% of the Earth's surface is covered by water,
and Hydrogen is a major component of water.
On the surface of the Earth, you really have to try hard
to be far away from a cheap source of Hydrogen.
Explanation:
The net force along the horizontal direction is

where f is the frictional force. We can find the frictional force by looking at the vertical forces acting on the couch:

From the definition of frictional force,


Therefore, the net force on the couch is

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 ).