Answer:
B
Explanation:
Potential difference has a SI Unit of Volt and its symbol is <em>V</em>. Hence answer is <u>B</u>.
A is wrong as it has the unit Joule <em>(J)</em> which is the SI unit for energy.
C is wrong as it has the unit Newton <em>(N)</em> which is the SI unit for force.
D is wrong as it has the unit Coulomb <em>(C)</em> which is the SI unit of charge.
Im not exactly sure but I think the answer is techtonic plates collide
They don't need gas because satellites rotate around the world using our planet's gravitational force as centripetal force. That as well as since there is no air in space, it doesn't have to work against air resistance. This way it doesn't lose energy by going around and around the Earth.
Hope this helps, have a BLESSED day! :-)