Chapter 4: The Laws of Motion

Isaac Newton

The British scientist ________, who lived from 1642 to 1727, published a set of three rules in 1687 that explained how forces and motion are related.

Gravity

________: an attractive force between any two objects that depends on the masses of the objects and the distance between them.

Moon

On the ________, the gravitational force on the astro- naut is less than it is on Earth.

Projectile

________: Anything thats thrown or shot through the air.

free fall

When all forces except gravity acting on an a falling object can be ignored, the object is said to be in ________.

Inertia

________: the tendency of an object to resist a change in its motion.

Third Law of Motion

________: describes action- reaction pairs this way: When one object exerts a force on a second object, the second one exerts a force on the first that is equal in strength and opposite in direction.

Gravity

________ is one of the four basic forces.

Inertia

the tendency of an object to resist a change in its motion

Second Law of Motion

states that the acceleration of an object is in the same direction as the net force on the object, and that the acceleration can be calculated from the following equation

Gravity

an attractive force between any two objects that depends on the masses of the objects and the distance between them

The Law of Universal Gravitation

gravitational force = (constant) x (mass 1) x (mass 2) / (distance) (squared)

Gravitational Force Equation

gravitational force(N)

Weight

The gravitational force exerted on an object

Weight Equation

weight (N) = mass (kg) X gravitational acceleration (m/s2)

Projectile

Anything thats thrown or shot through the air

Centripetal Acceleration

Acceleration toward the center of a curved or circular path

Centripetal Force

The net force exerted toward the center of a curved path

Momentum

the product of its mass and velocity

Formula

momentum (kg m/s) = mass (kg) X velocity (m/s)

Law of Conservation of Momentum

if a group of objects exerts forces only on each other, their total momentum doesnt change

First Law of Motion

states that if the net force acting on an object is zero, the object remains at rest, or if the object is moving, it continues moving in a straight line with constant speed.

Second Law of Motion

states that the acceleration of an object is in the same direction as the net force on the object, and that the acceleration can be calculated from the following equation:

Weight

The gravitational force exerted on an object

Centripetal Acceleration

Acceleration toward the center of a curved or circular path

Centripetal Force

The net force exerted toward the center of a curved path

Third Law of Motion

describes action-reaction pairs this way: When one object exerts a force on a second object, the second one exerts a force on the first that is equal in strength and opposite in direction

Momentum

the product of its mass and velocity.

Law of Conservation of Momentum

if a group of objects exerts forces only on each other, their total momentum doesn’t change.