Chapter 12 Science Vocab

Velocity

the speed and direction of a moving object

Force

a push or a pull

Net Force

combination of all forces acting on an object

Balanced Forces

two or more forces whose effects can cancel each other out and do not change the motion of an object

Unbalanced Forces

two or more objects acting on an object that do not cancel and cause the object to accelerate

Newton’s First Law of Motion

states that if the net force acting on an object is zero the object will remain at rest or move in a straight line with a constant speed

Friction

force that acts to oppose sliding between two surfaces that are touching

Gravity

a force that exists between any two objects that have mass

Acceleration

equals the change in velocity divided by the time for the change to take place; occurs when an object speeds up, slows down, and turns

Newton’s Second Law of Motion

states that an object acted upon by a net force will accelerate in the direction of the force and that the acceleration equals the net force divided by the object’s mass

Weight

gravitational force between an object and Earth

Center of Mass

point in an object that moves as if all of the object’s mass were concentrated at that point