5. What is the amount of work done when JoAnne throws a baseball 6.5 meters at a force of 40 newtons?

  W = 260 J

Explanation:

Work is defined by

          W = F. d

Bold type indicates vectors,

          W = F d cos θ

where tea is the angle between the force and the displacement, in this case the force is parallel to the displacement so the angle is zero and the

          cos 0=1

let's calculate

           W = 40 6.5

           W = 260 J

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it