Newton's law of universal gravitation, F = G × (m₁ × m₂) / r², how the pull grows with the masses involved and fades with the square of the distance between them, plus weight, W = m × g, the same pull acting on you at Earth's surface, the way the HESI A2 physics subtest tests this objective.
ObjectiveP.3.3Read4 minExam weightEnergy and Momentum ≈ 20% of Physics
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You can state Newton's law of universal gravitation and identify what each quantity in it controls.
You can predict how gravitational force changes when a distance or a mass changes, including the inverse-square drop-off.
You can calculate an object's weight from its mass using g = 9.8 m/s², and explain why that same g applies no matter how large or small the mass is.
What the lesson concludes
Every object with mass pulls on every other object with mass, not just Earth on you.
Gravitational force grows with the product of the two masses and falls with the square of the distance between their centres.
Double the distance and the force drops to one quarter; triple it and the force drops to one ninth.
Weight is universal gravitation applied at Earth's surface, W = m × g, with g about 9.8 m/s².
The falling object's own mass cancels out of g, which is why gravity accelerates every mass at Earth's surface by the same 9.8 m/s², and why nursing dosing works in kilograms of mass rather than a scale reading of weight.