Presentation on theme: "NOTES 3: Drawing a Force Diagram (AKA Free body Diagram)"— Presentation transcript:
1NOTES 3: Drawing a Force Diagram (AKA Free body Diagram) Force & MotionNOTES 3:Drawing a Force Diagram(AKA Free body Diagram)
2WHAT IS A FORCE DIAGRAM?A simple, labeled diagram that shows the forces acting on an object as arrows that indicate the magnitude and direction of the force.2N5N
3Newton Balanced forces Unbalanced forces VOCABULARYForce diagrams require a knowledge of the following:MAGNITUDEDIRECTIONNET FORCEAnd a review of…Newton Balanced forces Unbalanced forces
4MAGNITUDEThe amount of force applied to an object; the higher the force, the greater the magnitude
5DIRECTIONUm, duh?The place towards which an applied force is pushing or pulling an objectOn a force diagram, the direction is indicated by an arrow. The arrow points in the direction the force is moving the object.
6The combined force (magnitude and direction) acting on a object. NET FORCEThe combined force (magnitude and direction) acting on a object.
7the SI (standard international) unit for force Equal to: 1 kg x 1m/s2 NEWTON (N)the SI (standard international) unit for forceEqual to:1 kg x 1m/s2
8BALANCED FORCESWhen the magnitude and direction of more than one force acting on an object results in a net zero force
9UNBALANCED FORCESWhen the magnitude and direction of more than one force acting on an object results in a net force unequal to zero
10HOW TO DRAW A FORCE DIAGRAM Draw a square, rectangle, or circle to represent the object the force will be acting upon.Label the object!!Draw ONE arrow for each force that is acting upon the object.The size of the arrow reflects the magnitude of the force.The direction of the arrow shows the direction that the force is acting.Label each arrow you’ve drawn with the magnitude of the force.
11PRACTICE 1A book is resting on a tabletop. The book sits on the table with 5N worth of force.
12PRACTICE 1 What is the net force? Does the book move? 0 (zero) No (the book is at rest)
13PRACTICE 2Marissa and Nadia are playing tug of war. Marissa pulls the rope with 3N of force and Nadia pulls the rope with 4N of force.
14PRACTICE 2 What is the net force? rope4N3NWhat is the net force?1N to the right (the 3N of force in oppositedirections cancel other out leaving only 1N to the right)Who wins the tug-of-war?Nadia
15ALRIGHTY THEN…IF MORE THAN ONE FORCE ACTS ON AN OBJECT ALON G A STRAIGHT LINE, THE FORCES WILL REINFORCE OR CANCEL EACH OTHER OUT – DEPENDING ON THE DIRECTION AND MAGNITUDE OF THE FORCES.
16UNBALANCED FORCES In which examples were their nonzero net forces? Unbalanced forces result in nonzero net forces that will cause a change in speed or direction (or both) of the object’s motion.In which examples were their nonzero net forces?What happened to the speed/direction in those examples?
17REINFORCE10NNET FORCE :15N to the right5NThe net force is twice what either force would be alone. They combine forces (Ha Ha!) because they are acting upon the object in the same direction.