There are 60 minutes in an hour. Whatever distance a person crosses in 5 mins, he/she can cross 12 times that distance in 1 hour. So, in one hour the person could have crossed 12 X 600 = 7200 meters.
But, 1000 meters equal one kilometer. So, 7200m = 7.2 km. Thus, this person travels 7.2 km in one hour, and hence has a speed of 7.2 km/hr
In one of the most amazing coincidences in all of science,
the part of the electromagnetic spectrum that's visible to the
human eye is called "visible light".
Visible light is not 'divided' into anything. We mention the names
to seven of the colors in visible light. But all of the thousands of
OTHER colors that we can see are in there too, even though we
don't bother to list their names when we buzz through the rainbow
in the third grade.
The force on a charged particle on a magnetic field is given by:

where B is the magnitude of the field, q is the charge of the particle, v is its velocity and θ is the angle between the field and the velocity of the particle.
In this case we have that:
• The magnitude of the field is 0.09 T.
,
• The charge of the particle is 3.2 x 10 –19C .
,
• The velocity is 3.0 × 10 4 m/s
,
• The angle between the field and the velocity is 90°, since they are perpendicular.
Plugging these we have:

Therefore, the force on the charge is: