The intensity of the magnetic force F experienced by a charge q moving with speed v in a magnetic field of intensity B is equal to

where

is the angle between the directions of v and B.
1) Re-arranging the previous formula, we can calculate the value of the magnetic field intensity. The charge is

. In this case, v and B are perpendicular, so

, therefore we have:

2) In this second case, the angle between v and B is

. The charge is now

, and the magnetic field is the one we found in the previous part, B=2.8 T, so we can find the intensity of the force experienced by this second charge:
High temperature gives the hydrogen atoms enough energy to overcome the electrical repulsion between the protons. Fusion requires temperatures of about 100 million Kelvin (approximately six times hotter than the sun's core).

Work = force * distance
and newton*meters = Joule
In this case, work = 250N*50m = 12500 J
So the answer is D) 12,500 J
Answer:
because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits
When an unbalanced force acts on an object the change in the object state of rest or motion depends on the size and direction of the force.
If a body is at state of rest or motion, when an unbalanced external force acts on it, its starts moving in the direction of force and magnitude of its velocity or acceleration depends on the magnitude of force applied.