Chapter 10 Section 1: The Nature of Force

What is force?

-A force is a ______or a ______

-All Forces have a size and a ______

-A force can change the ______ of an object by either

changing the ______or the ______of the object

-The SI unit for force is the ______ (N)

II. Forces acting in objects.

-All forces ______on objects

-For any ______ that occurs, something has to______ the push

(You can’t push nothing!)

-The same is true for any ______

(eg) Some trains are so______ that extra locomotives

are added until the net force provided by all the locomotives

is______ enough to move the train.

-A force acting on an object ______mean ______ will occur

(eg) your exerting a force on the chair ______ sitting on

but it’s not moving because the ______ is also exerting a

force on the chair

-You cannot always tell what is ______ a force or what is

receiving a force.

(eg) Gravity, Static Electricity, Magnetism

III. Determining Net Force

-Net Force is the ______ of all the forces acting on an

object.

-Net force is determined by the ______ of the forces

-When forces act in the ______direction, you ______the forces

todetermine the net force. The net force will be in the ______

direction as the individual forces.

(eg) You and your Mom move the couch. You pull on one end of the couch with a force of 25 N and your Mom pushes on the other end on the couch with a force of 15 N. The forces are in the ______ so 25 + 15 = 40N of net force

-When two forces act in ______ directions, you subtract the

______force from the larger force to determine the net force.

The net force will be in the same direction as the ______force

(eg) Team 8B and the 8B teachers have a Tug of War. Team 8b exerts a force of 100N to the left and the 8B teachers exert a force of 500N to the right (opposite direction of the students). The Net Force would be 500 – 100 = 400N to the right, and the ______would ______the ______!!

-Force and Pressure are ______. Pressure is the______ of

force exerted on a given ______.

(eg) Bed of Nails and Magician: What is the net force of an object when you combine a force of 7N north with a force of 5N south?

IV. Balanced and unbalanced Forces

-If you know the ______ acting on an object, you can

determine the effect the net force will have on the object’s motion.

-Net force tells you whether the forces acting on the object are

______or unbalanced

-When the net force equals_____ the forces are______ and

the object ______ change it’s motion. It will either stay in

motion or it will remain at rest

(eg) Light hanging from the ceiling(gravity pulling down = force of cord pulling up), Bird’s nest in a tree, a hat on your head, a house of cards.

-When the net force is ______than zero the forces are

unbalanced and the object will produce a ______ in motion

(speed/ direction) It will cause the object to speed up, slow down,

stop, start, or change direction.

-An object can ______ to move when the unbalanced forces

are______.

(eg) When a ball is kicked, it receives an unbalanced force, but continues to move long after the force of the kick has ended