Unit 8: forces and energy vocab

Force

A push or pull exerted on an object 

friction

force that opposes the sliding motion between two touching surfaces

applied force

force causing a push o pull on an object not involving a string, rope or chain

air resistance

the force exerted by air that apposes the motion of an object moving through it

gravity

Attractive force between two objects that depend on the masses of the objects and the distance between them

acceleration 

rate of change of velocity; can be calculated by dividing the change in velocity by the remains it takes the change to occur 

balanced forces

forces are typically equal in strength and acting in opposite direction; objects remains at rest or in constant motion

unbalanced forces

forces may be unequal in strength or acting in direction NOT opposite each other; objects accelerates in direction of net force

inertia

tendency of an object to resist any can age in its motion

momentum 

property of a moving object that equals its mass times its velocity

motion

a change in an objects position relative to a reference point

velocity

the speed and direction of moving objects

impulse

force acting for a specific amount of time that results in a change in momentum; equal to the change in momentum 

law of conservation of momentum

sets that if no external forces act on a group of objects, their total momentum does not change 

Newtons 1st law of motion

states that an objects moving at a constant velocity keeps moving at velocity unless an unbalanced force acts on it

newtons 2nd 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 equals the net force divided by its mass 

newtons 3rd law of motion 

states that when one object exerts a force on a second object, the second object exerts a force on the first object that is equal in strength and in the opposite direction