Gravity and Mass
how does an object's mass relate to its gravity?
Objects with more mass usually have stronger gravity.
What direction is the pull of the Sun's gravity on earth?
directly towards the center of the sun.
A heavy metal ball rests on a stretched rubber sheet. A glass marble rolls across it. How is this model different from real orbits in the solar system?
Friction between the marble and sheet slows the marble. Planets move through space with almost no friction.
Two identical moons orbit the same planet. Moon A is closer to the planet than Moon B. Which moon experiences a stronger gravitational pull from the planet?
Moon A
A moon moves around a planet. How does gravity help keep the moon in orbit?
It pulls the moon toward the planet and changes the moon's direction.
Two round objects are a set distance apart. What two changes will make their gravitational pull stronger?
Increasing the mass and cutting the distance.
If the Sun's gravity stopped pulling on Earth, which path would Earth follow because of inertia?
A direct line in the direction it was traveling.
Why did astronomers replace Ptolemy's Earth-centered model with Copernicus's Sun-centered model?
The Sun-centered model explained why outer planets sometimes appear to move backward across the sky.
How can a moon and its planet can both be in motion?
The moon orbits the planet while the planet orbits a star.
Two objects keep the same masses but move farther apart. What happens to the gravitational pull between them?
It gets weaker.
An astronaut travels from Earth to the Moon. What happens to the astronaut's mass and weight?
The astronaut's mass stays the same, but weight decreases.
What is true about the orbital speed of planets as distance from the sun increases?
As distance increases, orbital speed decreases because the Sun's pull is weaker.
How is mass arranged differently in the solar system and the Milky Way Galaxy?
In the solar system, the Sun holds most of the mass. In a galaxy, mass is spread among many stars, gas, dust, and a supermassive black hole at the center.
A student increases the Sun's mass in a model but keeps Earth's distance the same. What should the model predict about the Sun's gravitational pull on Earth?
It increases.
Stars and gas move within the Milky Way Galaxy. What force helps hold the galaxy together?
Gravity among the matter in the galaxy
How many times stronger is Earth's gravity compared to the moon?
6 times
The Sun has most of the solar system's mass. How does this shape the solar system?
The Sun's gravity guides the orbits of the bodies around it.
A star moves through the Milky Way Galaxy. What force helps shape its motion?
Gravity from stars, gas, and other matter in the galaxy
A star moves through the Milky Way Galaxy. What force helps shape its motion?
Gravity from stars, gas, and other matter in the galaxy
A satellite moves closer to Earth. If its mass stays the same, how does Earth's gravitational pull on it change?
It becomes stronger.
What percentage of the solar system's gravity is contained by the Sun?
99.86%
What holds the Oort Cloud in place?
The Sun
A student models a planet's path around the Sun as an ellipse. Which statement best describes the Sun's position in this path?
The Sun located slightly off-center at one focal point.
An object moving near a planet follows a curved path. What explanation best describes the role of the planet's gravity?
It pulls on the object and changes its direction.
describe Galileo's discovery on free fall?
In a vacuum, all objects accelerate downward at the same rate regardless of mass.