Gravity Basics
What is gravity?
A force that pulls objects toward each other.
How does mass affect gravitational force?
The greater the mass, the stronger the gravitational force.
What force keeps the planets in orbit around the Sun?
The suns gravitational force.
What happens to an object’s weight if gravity increases?
Its weight increases.
Why do we stay on the ground instead of floating into space?
Because Earth’s gravity pulls us downward.
Who discovered that all objects attract each other with a gravitational force?
Isaac Newton
How does distance affect gravitational force?
The greater the distance, the weaker the gravitational force.
Why does the Sun have the strongest gravitational pull in the solar system?
Because it has the greatest mass.
What evidence supports the idea that gravity depends on mass?
More massive planets have stronger gravity.
Why do satellites orbit Earth instead of falling down?
They move fast enough forward to stay in orbit while falling around Earth.
What direction does gravity always pull objects?
Toward the Center of the earth
If Earth were twice as massive, how would gravity on its surface change?
It would be stronger.
What two factors determine the strength of gravitational attraction between objects?
Mass and Distance
What data could support the claim that the Moon’s gravity is weaker than Earth’s?
Objects weight less on the moon than on the earth.
What causes ocean tides on Earth?
The gravitational pull of the Moon (and the Sun).
What keeps the Moon in orbit around Earth?
Earth's gravitational force
Why do astronauts feel “weightless” in orbit even though gravity still acts on them?
They are in free fall around Earth, constantly falling but moving forward.
Why do smaller planets like Mercury have less gravity than Earth?
They have less mass.
How can you test how mass affects gravity using different-sized balls and a balance scale?
Compare their pull or weight — heavier balls show more gravitational pull.
Why do objects fall at the same rate on Earth, regardless of their mass?
Air resistance aside, gravity accelerates all objects equally.
What tool do scientists use to measure the strength of gravity on Earth?
Spring Scale
If two planets have the same mass but one is twice as far from the Sun, which has less gravitational pull from the Sun?
The one farther from the Sun.
What would happen to Earth if the Sun’s gravity suddenly disappeared?
Earth would move off a straight line into space.
What kind of data would show that gravity decreases with distance?
Measuring weaker attraction between objects farther apart.
Why would you weigh less on Mars than on Earth?
Mars has less mass, so it exerts a weaker gravitational pull.