Half the grain is unloaded from one of two docked ships, the distance unchanged. The pull between the ships…
Two pairs of crates sit in a warehouse. Pair one holds heavy crates, far apart. Pair two holds light crates, close together. In which pair is the gravitational force stronger? You now hold the tools to answer, most of the time.
Rank gravitational forces with the two factors you know, mass and distance, taken one at a time.
If the masses match, distance decides: the closer pair's force is stronger. If the separations match, mass decides: the heavier pair's force is stronger.
The same two masses at 1 m, 2 m, and 3 m rank by distance alone: the 1 m pair strongest, the 3 m pair weakest.
Two pairs of identical barrels: pair A's barrels sit 10 m apart, pair B's sit 4 m apart. In which pair is the gravitational force stronger?
Compare one factor at a time:
The masses match: all four barrels are identical.
So distance decides: the closer pair's force is stronger.
Pair B's barrels are closer.
The force within pair B is stronger.
Identical buoy pairs: A 2 m apart, B 5 m, C 8 m. Which pair's pull is strongest?
Two more pairs sit at the same 5 m separation: pair C's barrels hold 60 kg each, pair D's hold 20 kg each. In which pair is the gravitational force stronger?
Compare one factor at a time:
The separations match.
So mass decides: the heavier pair's force is stronger.
Pair C's barrels hold more.
The force within pair C is stronger.
Two pairs of canoes float at the same spacing: one pair empty, one pair fully loaded. Which pair's pull is stronger?
When both factors agree, heavier and closer, the verdict is certain. When the factors disagree, heavier but farther, the two rules alone cannot decide.
Back to the warehouse: pair one is heavier but farther. The factors disagree, so hold that question for one lesson.
Three pairs of identical drums: pair X 3 m apart, pair Y 9 m apart, pair Z 5 m apart. Which order runs strongest pull to weakest?
Pair J: two 90 kg crates 8 m apart. Pair K: two 40 kg crates 2 m apart. Each rule says only stronger or weaker — never how much. Using only the mass rule and the distance rule, what can be said?
Pair L: two 40 kg drums 3 m apart. Pair M: two 90 kg drums 3 m apart. Pair N: two 90 kg drums 6 m apart. Which pair's pull is strongest?