The answer to this question is that --- The momentum possessed by a body is generally defined as the product of its mass and velocity.
Momentum is a vector and it also has magnitude as it is the product of the multiplication of the mass and velocity.
Answer: 
Explanation:
The equation to calculate the center of mass 
of a particle system is:
In this case we can arrange for one dimension, assuming the geometric center of the Earth and the ladder are on a line, and assuming original center of mass located at the Earth's geometric center:
Where:
is the mass of the Earth
is the mass of 1 billion people
is the radius of the Earth
is the distance between the center of the Earth and the position of the people (2 m above the Earth's surface)
This is the displacement of Earth's center of mass from the original center.
Is there any answers? Or is it asking you to choose?
Answer:
Autotrophs
Explanation:
When you go down a food chain continuing to ask "what does it eat?" the last living thing that you will land upon is an autotroph.
Autotrophs are the primary producers as they (photoautotrophs) use the energy either from the sun to prepare there food by the process of photosynthesis or, more rarely, obtain chemical energy through oxidation (chemoautotrophs) to make organic substances from inorganic ones.
Autotrophs get consumed by the primary consumers in the food chain.
