Efficiency is completing a task as fast a possible the the least amount of effort.
answer:They are too close to the sun!
Explanation:Because Mercury is so close to the Sun and its gravity, it wouldn't be able to hold on to its own moon. Any moon would most likely crash into Mercury or maybe go into orbit around the Sun and eventually get pulled into it.Same with Venus!
Let us first know the given: Tennis ball has a mass of 0.003 kg, Soccer ball has a mass of 0.43 kg. Having the same velocity at 16 m/s. First the equation for momentum is P=MV P=Momentum M=Mass V=Velocity. Now let us have the solution for the momentum of tennis ball. Pt=0.003 x 16 m/s= ( kg-m/s ) I use the subscript "t" for tennis. Momentum of Soccer ball Ps= 0.43 x 13m/s = ( km-m/s). If we going to compare the momentum of both balls, the heavier object will surely have a greater momentum because it has a larger mass, unless otherwise the tennis ball with a lesser mass will have a greater velocity to be equal or greater than the momentum of a soccer ball.
To be honest I’m not sure you might want to ask Newton as he’s an expert best of luck