Hydroelectricity is the best answer.
This is an article by the EIA, but the pie graph is the most helpful: https://www.eia.gov/energyexplained/?page=us_energy_home
Answer:Shifted towards Left by distance of 2.243 m
Explanation:
Given
Mass of john 
Mass of barbara 
John is standing at 
Barbara is standing at 




Now if they change their Position then



Thus we can see that center of mass shifted towards left by a distance of
because heavier is shifted towards left
Regardless of what direction an object is moving, the acceleration
due to gravity is always directed toward the center of the Earth.
That's the direction commonly known as "down".
It is the number in front of the equation