# Science - ch.2 (Forces) Flashcards

 balanced forces a net force of zero centripetal force a force that acts perpendicular to the direction of motion and towards the center of attraction (only when an object is moving in a circular motion) compression force a squeezing force applied to an object that can make the object shrink contact force a force that is exerted only when objects are touching elastic force the force exerted by a material when it is stretched or compressed force a push or a pull friction a contact force that acts to resist sliding between two touching surfaces gravity an attractive force between all objects that have mass net force the combination of all the forces acting on an object Newton's first law of motion if the net force on an object is zero, an object at rest remains at rest (and an object in motion remains in motion without a change in its velocity) Newton's second law of motion acceleration equals the net force exerted on the object divided by the object's mass Newton's third law of motion when one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first object noncontact force a force exerted when objects are not touching examples of noncontact forces (3) gravitational forcemagnetic forceelectric force normal force a force exerted by an object perpendicular to the surface of the object tension force pulling force applied to an object that can make the object stretch Law of universal gravitation all objects are attracted to each other with a force that depends on the masses of the objects and the distance between them (the larger the mass, the greater the force; the closer the distance, the greater the force) unbalanced forces when the net force on an object is not zero static friction the force between two surfaces in contact that keeps them from sliding when a force is applied sliding friction the force that opposes movement between two objects sliding against each other force pairs the forces two objects exert on each other (they act in opposite directions and are the same size) action and reaction action force: the force applied by one object on anotherreaction force: the equal but opposite force the second object exerts on the first AuthorSamsam ID143540 Card SetScience - ch.2 (Forces) Flashcards DescriptionScience - Ch.2 (Forces) Flashcards Updated2012-03-24T23:23:09Z Show Answers