Answer:
a) always. b) electric field lines are defined by the path positive test charges travel.
Explanation:
By convention, field lines always follow the direction that it would take a positive test charge (small enough so it can´t disrupt the field created by a charge distribution), under the influence of an electric field, at the same point where the test charge is located.
So any positive charge, subject to an electric field influence, moves along the field line that passes through its current position, in the same way that a positive test charge would.
We could say also that the electric force on a positively charged particle is in the same direction as the electric field that produces that force (due to some charge distribution) , which is true, but it doesn´t explain why.
The principle that
describes the force on a charge in a magnetic field was named for Hendrik Lorentz, and the principle
is named as Lorentz force.
Hendrik Antoon Lorentz<span> <span>(18 July 1853 – 4 February 1928) was a Dutch </span></span>physicist<span> <span>who shared the 1902 </span></span>Nobel Prize in Physics<span> <span>with </span></span>Pieter Zeeman<span> <span>for the discovery and theoretical explanation
of the </span></span>Zeeman effect<span>.<span> </span></span>
I think that would be the moon
"too small to clear objects that are in its orbital path" , which means that it probably not a planet.
hope this helps
The medicine ball wall hit the ground faster, if that makes sense to you
