Physics: Newton's Laws, Motion, and Inertia for Students

What was one of Galileo's key arguments about motion?

A force is only needed to keep an object moving when friction is present.

What is inertia?

The property of a body to resist changes to its state of motion.

What does Newton's first law state?

Every object continues in a state of rest or uniform speed in a straight line unless acted on by a nonzero net force.

What is another name for Newton's first law of motion?

The law of inertia.

How does mass relate to inertia?

The more mass an object has, the greater its inertia and the more force it takes to change its state of motion.

What is the SI unit of mass?

Kilogram (kg).

What is the SI unit of force?

Newton (N).

What happens to objects in motion if no unbalanced forces act on them?

They remain in motion.

What did Galileo conclude about a ball rolling on a smooth surface?

It has almost constant velocity and would move forever if friction were absent.

What is the relationship between mass and weight?

Weight is the force of gravity on an object and depends on its location, while mass remains constant regardless of location.

What effect does friction have on motion?

Friction acts between materials that touch as they move past each other, opposing motion.

According to Newton's first law, what will happen to dishes on a table when the tablecloth is quickly pulled?

The dishes tend to remain at rest because there is not enough force to move them.

How long will an object move in a straight line in a force-free environment?

Indefinitely.

What are two factors that can change the state of motion of an object?

Friction and an external force.