Forces in Space

What model did scientists settle on a few centuries ago?

• The heliocentric model

• The geocentric model

• The flat Earth model

• The spherical Earth model

Answer explanation

A few centuries ago, scientists settled on the heliocentric model. This model, suggested by Copernicus, postulated that the Earth and other planets revolve around the sun, which is at the center of the solar system. This was a drastic shift from the previously accepted geocentric model, which placed Earth at the center. The heliocentric model is now universally accepted.

Tags

8.MS-ESS1-2

6.MS-PS2-4

What is gravity?

• The force of attraction between any two objects

• The force that prevents objects from moving in a straight line

• The force that holds planets in orbit around the Sun

• The force that keeps objects from floating off into space

Answer explanation

Gravity is the fundamental force that attracts two objects towards each other. This force of attraction exists between any two objects, not just between a planet and the objects within its vicinity. Therefore, the correct answer to the question is: 'The force of attraction between any two objects'.

Tags

6.MS-PS2-4

8.MS-ESS1-2

What is mass?

• The measurement of the force of gravity on an object

• The amount of matter in an object

• The push or pull on an object

• The location of an object in the solar system

Answer explanation

Mass is a physical property that indicates the amount of matter contained in an object. Despite the common misconception, it is not directly related to the force of gravity on an object, the push or pull on an object, or its location in the solar system. So, in response to the question 'What is mass?', the correct answer is 'The amount of matter in an object'.

Tags

6.MS-PS2-4

What factors make the force of gravity stronger?

• More mass and closer distance

• Less mass and closer distance

• More mass and farther distance

• Less mass and farther distance

Answer explanation

The strength of the gravitational force depends on two factors: mass and distance. The gravitational force becomes stronger with more mass and less distance between the objects. The correct choice, 'More mass and closer distance', perfectly explains this as it suggests that gravity is stronger when the objects have more mass and are closer together.

Tags

6.MS-PS2-4

What is inertia?

• The force of attraction between any two objects

• The measurement of the force of gravity on an object

• The amount of matter in an object

• The tendency of an object to stay at rest or in motion

Answer explanation

Inertia is the property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. Hence, the correct answer is 'The tendency of an object to stay at rest or in motion'. The other options are describing different properties and do not accurately define inertia.

Tags

6.MS-PS2-4

What does Newton's 1st Law of Motion state?

• An object at rest will stay at rest, and an object in motion will stay in motion at a constant speed and direction unless acted on by an outside force

• An object at rest will stay at rest, and an object in motion will slow down and eventually stop

• An object at rest will start moving, and an object in motion will change its speed and direction

• An object at rest will start moving, and an object in motion will stay in motion at a constant speed and direction

Answer explanation

Newton's 1st Law of Motion, also known as the Law of Inertia, states that an object at rest will stay at rest, and an object in motion will stay in motion at a constant speed and direction unless acted on by an outside force. This law emphasizes the resistance of an object to change its current state, be it rest or motion.

Tags

6.MS-PS2-4

What is the role of gravity in creating an orbit?

• Gravity holds the planet in orbit by pulling the planet towards the Sun

• Gravity keeps the planet moving at a constant speed

• Gravity prevents the planet from floating off into space

• Gravity creates a balance with inertia to keep the planet in a constant orbit

Answer explanation

Gravity plays a critical role in the formation of an orbit. The correct answer is that gravity holds the planet in orbit by pulling the planet towards the Sun. It is the gravitational force that keeps the planet from flying off into space, while allowing it to move around the Sun in a path known as an orbit.

Tags

6.MS-PS2-4

What would happen if all inertia disappeared from our solar system?

• Planets would stop moving and stay at rest

• Planets would continue moving in a straight line forever

• Planets would start moving in random directions

• Planets would float off into space

Answer explanation

Inertia is the property of matter that resists changes in motion. If all inertia disappeared, objects would not resist changes in their motion. However, the absence of inertia doesn't imply absence of momentum. Therefore, according to the first law of motion, in the absence of external forces, the planets would continue their motion in a straight line forever.

Tags

6.MS-PS2-4

What would happen if all gravity disappeared from our solar system?

• Planets would stop moving and stay at rest

• Planets would continue moving in a straight line forever

• Planets would start moving in random directions

• Planets would float off into space

Answer explanation

If all gravity disappeared from our solar system, the planets would continue moving in a straight line forever due to inertia. In the absence of gravity, there would be no force to pull them into a curved path, hence they would just continue on the same straight trajectory indefinitely.

Tags

6.MS-PS2-4

Why is it important to have both forces of gravity AND inertia to keep planets in orbit?

• Gravity keeps the planet in orbit, while inertia keeps the planet moving at a constant speed

• Gravity prevents the planet from floating off into space, while inertia keeps the planet moving in a straight line

• Gravity holds the planet in orbit by pulling the planet towards the Sun, while inertia keeps the planet moving at a constant speed

• Gravity creates a balance with inertia to keep the planet in a constant orbit

Answer explanation

Orbits are due to a delicate balance between gravity and inertia. Gravity pulls the planet towards the sun, providing a centripetal force. Inertia, the resistance to changes in motion, tends to keep the planet moving in a straight line. Both forces interact to keep the planet in a constant, elliptical path known as orbit, thereby making the option 'Gravity creates a balance with inertia to keep the planet in a constant orbit' correct.

Tags

6.MS-PS2-4