Forces Third Law First Law and Equilibrium Second Law and Acceleration

May the Force be with you. Either a push or a pull Unit: kg m s-2 or newton, N Two types: Contact Force Non-contact Force

Types of Forces: Contact Force Tension Friction pull Normal Force

Types of Forces: Contact Force Upthrust Drag

Thrust Thrust Types of Forces: Contact Force Replace it with your original text. Replace it with your original text. Thrust Replace it with your original text. Thrust Replace it with your original text.

Thrust Lift Types of Forces: Contact Force Replace it with your original text. Replace it with your original text. Thrust Replace it with your original text. Lift

Types of Forces: Non-Contact Force Weight Replace it with your original text. Replace it with your original text. Thrust Replace it with your original text. Weight

Types of Forces: Non-Contact Force Replace it with your original text. Replace it with your original text. Replace it with your original text. Electrical Force Magnetic Force

Weight Weight Normal force Air resistance

Weight Thrust Drag Friction Normal Force

Weight Thrust Drag Upthrust

Third Law Action and Reaction Law Page 56 Conditions: The two forces must be the of the same type The two forces are acting on different bodies Applies in all circumstances Force always exists in pairs Drawing Free-Body Diagrams

Action and Reaction Forces

Action and Reaction Forces

First Law Law of Inertia Page 53 A body at rest will be at rest forever unless a net force acts on it to start it in motion A body in motion will continue to move at Constant speed In the same direction Forever unless a net force acts on it to Change its speed Change its direction Change both

Balanced forces

Balanced forces The book stays still!

The airplane moves forward at constant speed! Balanced forces The airplane moves forward at constant speed!

The car moves at constant speed! Balanced forces Thrust Drag Friction The car moves at constant speed!

Second Law Law of Dynamics If a net force is acting on a body, then it will accelerate. The magnitude of the acceleration is proportional to the magnitude of the net force but inversely proportional to the mass. The direction of the acceleration is the same as the direction of the net force. Equation Definition of a newton (page 55)

Unbalanced Forces The car moves from rest. The car speeds up.

Unbalanced Forces The car slows down to stop. The car slows down.