The generation of a magnetic field by an electric current is _electromagnetism_.
If the billiard ball is going at the constant speed and contains its mass then the momentum WONT be changing. But realistically you have external forces like friction and air resistance changing the velocity thus changing the momentum. In this case momentum is not conserved because you're introduction an external force.
Explanation:
<em>hopes </em><em>it's </em><em>h</em><em>elped </em><em>uh </em><em>mate</em><em>!</em>
<span>610 kg far from the fulcrum a 44-kg girl need to sit to balance the boy. </span>
