Forces A force is a push or pull
- Slides: 10
Forces • A force is a push or pull upon an object resulting from the object's interaction with another object. • all forces (interactions) between objects can be placed into two broad categories: – contact forces – forces resulting from action-at-a-distance
Forces Contact Forces Frictional Force Tension Force (Pull) Normal Force (Push) Air Resistance Action-at-a-Distance Forces Gravitational Force Electrostatic Force Magnetic Force
How to draw a force diagram: 1. Object is represented by a dot 2. Direction shown by arrow (pointing away from the object) 3. Amount/strength shown by length of arrow 4. Label: types of force Ffriction FGravity FNormal FTension FElectrostatic FMagnetic FBuoyancy Ff FG FN FT FE FM FB 5. Label: Force acts… “On <object> By <object> “
How to draw a force diagram: Step 1: Object is represented by a dot.
Step 2/3: Add arrows Direction Amount/strength
Step 4: Label types of force Ffriction Ff FGravitational FG FNormal FN FTension FT FElectrostatic FE FMagnetic FM FAir resistance FA FN Ff FT FG
Step 5 -Label: Force acts On <object> By <object> FN On dog By ground Ff FT On dog By friction On dog By leash FG On dog By Earth
Describing Forces in Free Body Diagrams FNormal On person By ground FGravity On person By Earth FNormal Ffriction On person By ramp FGravity On person By Earth
Sum of forces on objects at rest are always equal to ZERO We call Σ forces (sum of forces) the net force (Fnet) No unbalanced forces Fnet= 0 N When the diagram has no unbalanced forces, it means that the net force is zero
Exit ticket: force diagram • A book at rest on a table
