A student says the pull between two objects grows when either one gains mass, the distance unchanged. Is the student correct?
A space probe coasts away from Earth with its engines off. Earth never lets go of it. But the force on it changes all the way out.
Nothing about the probe's or Earth's mass changes on this trip. Only the distance between their centers grows. Distance is the second factor.
As the probe travels farther from Earth, the gravitational force on it grows weaker. The masses did not change. Only the distance did.
The distance that matters runs between the centers of the two objects.
Moving closer works the other way: as two objects approach, the force between them strengthens.
However far apart two masses sit, a trace of the force remains. The force weakens; it never reaches zero.
A comet swings in from far beyond Mars toward the Sun. What happens to the force from the Sun on the comet as it approaches?
Write down what changed:
The distance between the comet's center and the Sun's center decreases. Both masses are unchanged.
Apply the rule:
Decreasing the distance increases the force.
The force from the Sun on the comet increases.
Two kayaks drift toward each other on a still lake. The pull between them…
The same comet rounds the Sun and recedes again. What happens to the force now?
Write down what changed:
The distance between the centers increases again.
Apply the rule:
Increasing the distance decreases the force.
The force from the Sun on the comet decreases. However far the comet goes, the force never reaches zero.
A student says that as two spacecraft separate, the pull between them weakens but never becomes zero. Is the student correct?
A supply capsule coasts from the space station out toward the Moon, all masses unchanged. Earth's pull on the capsule…
A rocket climbs from its launch pad to high above the atmosphere. Which statement about Earth's pull on the rocket is correct?
A lunar lander descends toward the Moon's surface, all masses unchanged. The Moon's pull on the lander…