Physics Forces and Motion

Flashcards covering key vocabulary terms and concepts related to forces and motion, as outlined in the lecture notes.

Contact Force

A force that happens when two objects physically touch each other (ex: pushing, pulling, friction)

What does the 2nd law allow scientists to calculate?

Allows scientists to calculate an object's acceleration using the formula: Force = mass x acceleration.

Why do astronauts weigh less than space?

Astronauts weigh less because they are falling around Earth, feeling almost no weight despite Earth's gravity.

What effect of balance and unbalanced forces have on a moving car?

Balanced forces keep the car moving at the same speed and direction. Unbalanced forces cause the car to speed up, slow down, or change direction.

How does a force pair affect you if you’re jumping in the air?

When you jump, you push down on the ground. The ground pushes up on you with an equal and opposite force, which lifts you into the air. This is Newton’s Third Law.

Newton's Third Law

For every action, there is an equal and opposite reaction.

Law of Conservation of Momentum

Momentum in a group of objects stays the same unless an outside force acts on them.

How does law of conservation of momentum apply to a bowling ball striking pins?

When a bowling ball hits the pins, it transfers its momentum; total momentum of the system remains the same.

What creates friction?

Created when rough surfaces of two objects rub against each other, causing resistance to motion.

Apply friction to a situation.

When sliding a book across the table, it slows down because friction between the book and the table resists the motion.

Force

A push or pull of an object.

Momentum

A measure of how hard it is to stop a moving object; calculated as Momentum = mass x velocity.

Force Pair

Two forces that are equal in size and opposite in direction. (Newtons 3rd law)

Mass

The amount of matter in an object.

Weight

The force of gravity pulling on an object.

Inertia

An object's resistance to change in motion.

Centripetal Force

A force that pulls an object toward the center of a curved or circular path.

Distance

How far one point is from another object.

Pull

A force that brings an object toward you.

First Law of Motion

An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an unbalanced force. (ex: a soccer ball won’t move until someone kicks it)

Second Law of Motion

Acceleration depends on an object's mass and the force applied; expressed as F = ma. (ex: a heavier cart needs more force to accelerate than a lighter cart)

Third Law of Motion

For every action, there is an equal and opposite reaction. (ex: a rocket pushes gas downward, and the rocket moves upward)