Calculate the force of gravity on a 1-kilogram box located a point 1.3x10^7 meters from the center of earth if the force on a 2.5-kilogram box at the same point is 6.1 newton’s.

The force of gravity on the 1 kg box is 2 N.

The formula for the force of gravity F on an object with mass m is

F = (GmM)/d²

Since G, M , and d are the same for both objects, (GM)/d² = a constant = k ). Then, we can write

F = km

F₂/F₁ = m₂/m₁

F₂ = F₁ × m₂/m₁

If the 2.5 kg box is object 1,

F₂= 6.1 N × (1 kg/2.5 kg) = 2 N

Note: The answer can have only one significant figure because that is all you gave for the mass of the 1 kg object.

the answer for sodium is 0.186

the answer for rubidium is 0.251