It is b. sodium because it is in group 1
If the box is moving at constant velocity, net force must be zero, so:
F + fr = 0
fr = -F
<u>fr = -40 N</u>
<span>When the electric current flows out of the
page and the direction of the magnetic field is counter-clockwise. The magnetic
field that is made by an electric current is said to be always leaning
perpendicularly to the direction of the current flow.</span>
It goes in the downward direction
