SC.8.E.5.4 Gravity

Which configuration will result in the greatest gravitational force?

• small masses far apart

• large masses far apart

• small masses close together

• large masses close together

The distance between objects, along with the masses of the objects, affect the gravitational force between the objects. Which statement is true according to Newton’s law of universal gravitation?

• When the masses of objects increase, gravitational force decreases

• When distance between objects increases, gravitational force decreases.

• When distance between objects decreases, gravitational force decreases

• When the masses of objects decrease, the distance between objects decreases.

Which term best describes the shape of the orbits of planets in our solar system?

• centripetal

• circular

• elliptical

• spherical

Kevin is describing the orbit of Earth. At what point in Earth’s orbit is Earth closest to the sun?

• when Earth reaches aphelion

• when Earth reaches its average distance from the sun

• when Earth reaches perihelion

• when Earth reaches its slowest speed

Diana is explaining centripetal force to some younger students. Which example illustrates the concept of centripetal force?

• Centripetal force is a force that makes a body follow a curved path.

• Centripetal force is a force that makes objects move in straight lines.

• Centripetal force is a force that is directed away from a center of rotation.

• Centripetal force is a force in which a smaller body acts gravitationaly on a larger body.

Which term describes a small body from which a planet forms?

• orbit

• planetesimal

• solar nebula

• protoplanetary disk

Phillip wants to model the formation of a planet. What would his model for a planetesimal look like?

• a rotating cloud of gas and dust from which the sun and planets formed

• an elliptical path that a body follows as it travels around another body in space

• a disk of material surrounding a young star or protostar that may eventually form planets

• a small body from which a planet originated during the early development of the solar system

What role did gravity play in the formation of the sun?

• Gravity caused the protoplanetary disk to become a planetesimal, which became the sun.

• Gravity caused the protoplanetary disk to rotate and form a solar nebula, which became the sun

• Gravity caused the solar nebula to collapse toward the center, causing the center to be dense and hot.

• Gravity caused small particles to collide to form larger particles called planetesimals, which eventually formed the sun.

Eric is creating a timeline of the formation of the solar system. Which flow chart best describes the formation of the solar system?

• solar nebula ® protostellar disk ® nuclear fusion ® sun ® planetesimals ® planets

• solar nebula ® protostellar disk ® nuclear fusion ® planetesimals ® planets ® sun

• protostellar disk ® nuclear fusion ® sun ® solar nebula ® planetesimals ® planets

• solar nebula ® nuclear fusion ® sun ® planets ® planetesimals ® protostellar disk

Which statement best describes the role of gravity and centripetal force in the motion of planets around the sun?

• Gravity provides the centripetal force that keeps planets in orbit.

• The sun's gravity causes planets to move forward in a straight line.

• A planet's orbit is the result of forward motion and unbalanced forces.

• Centripetal force is an unbalanced force causing planets to move in a circular path.