Physics Vocab M1-3

What is physics?

the study of matter, energy, motion, and forces

What is another name for Newton’s First Law?

The Law of Inertia

What is inertia?

An object's resistance to a change in its motion.

What determines how much inertia an object has?

Its mass

Which has more inertia: a truck or a bicycle?

A truck because it has more mass.

What is net force?

The overall force acting on an object after all forces are combined

What are balanced forces?

Forces that cancel each other out, producing zero net force

What are unbalanced forces?

Forces that do not cancel out, producing a nonzero net force

What is equilibrium?

A condition in which the net force on an object is zero.

What is static equilibrium?

An object is at rest with zero net force

What is dynamic equilibrium?

An object moves at constant velocity in a straight line with zero net force.

What is support force?

he upward force a surface exerts on an object resting on it

What is mass?

The amount of matter in an object and a measure of its inertia

What is weight?

the gravitational force acting on an object

What is the difference between mass and weight?

Mass measures matter and inertia; weight measures gravitational force

What unit is mass measured in?

Kilograms (kg)

What unit is force and weight measured in?

Newtons (N)

What did Galileo contribute to the idea of inertia?

He showed that objects can continue moving without a continuous push when friction is absent

What did Aristotle believe about motion?

He believed a continuous force was needed to keep an object moving.

What is the formula for speed?

Speed = Distance / Time

What is average speed?

Total distance traveled divided by total time

What is instantaneous speed?

The speed of an object at one particular moment

What is velocity?

Speed in a specific direction

What is the difference between speed and velocity?

Speed has magnitude only; velocity includes magnitude and direction

What is a scalar quantity?

A quantity with magnitude but no direction

What is a vector quantity?

A quantity with both magnitude and direction

Is speed a scalar or vector quanity?

Scalar quanity

Is velocity a scalar or vector quanity?

Vector quanity

What is acceleration?

The rate at which velocity changes over time

What is the formula for acceleration?

Acceleration = (Final velocity - Initial velocity) / Time

What is the unit of acceleration?

Meters per second squared (m/s²)

What are three ways an object can accelerate?

It can speed up, slow down, or change direction

What is free fall?

Motion in which gravity is the only force acting on an object

What is the vertical velocity of an object at the highest point of its upward flight?

Zero for an instant, while its downward gravitational acceleration continues

What is the formula for Newton's Second Law?

F = ma

What does F represent in F = ma?

Net force, measured in newtons (N)

What does m represent in F = ma?

Mass, measured in kilograms (kg)

What does a represent in F = ma?

Acceleration, measured in meters per second squared (m/s²)

What happens to acceleration when force increases and mass stays the same?

Acceleration increases

What happens to acceleration when mass increases and force stays the same?

Acceleration decreases

What happens if the net force doubles while mass stays constant?

Acceleration doubles

What happens if mass doubles while net force stays constant?

Acceleration is cut in half

What is the formula for acceleration using force and mass?

a = F/m

What is the formula for mass using force and acceleration?

m = F/a

What is the formula for weight?

W = mg

Does mass change when an object moves to the Moon?

No, mass stays the same

Does weight change when an object moves to the Moon?

Yes, because the Moon has weaker gravity

What is air resistance?

A force that opposes an object's motion through air

What is terminal speed?

The constant falling speed reached when air resistance balances gravity

What is the net force on an object falling at terminal speed?

Zero

Does an object at terminal speed have acceleration?

No, its acceleration is zero

What is Newton's Third Law of Motion?

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

What are action-reaction forces?

Equal and opposite forces that two objects exert on each other

How does walking demonstrate Newton's Third Law?

your foot pushes the ground backward, and the ground pushes you forward

How does swimming demonstrate Newton's Third Law?

A swimmer pushes water backward, and water pushes the swimmer forward

What is the difference between Newton's First and Third Laws?

The First Law explains inertia; the Third Law explains action-reaction force pairs

What is the difference between Newton's Second and Third Laws?

The Second Law explains how net force causes acceleration; the Third Law explains how interacting objects exert forces on each other

What are the three important characteristics of action-reaction forces?

They are equal in magnitude, opposite in direction, and act on different objects