DAILY QUESTION January 7, 2009 1. What is the definition of force?
Transcript of DAILY QUESTION January 7, 2009 1. What is the definition of force?
DAILY QUESTION
January 7, 2009
1. What is the definition of force?
Agenda 1/7/09
• Daily Question• Partner Check – Problems Wksht• Check-in: Problems Wksht• Chapter 10 – Motion• New Read Aloud! “Life As We Knew It”• Assignments:
1. Study for Quiz on 1/9
Force
• Anything that changes the state of rest or motion of an object
Net Force
• The combination of all of the forces acting on the object.– Balanced forces = net force of zero
• Do not cause a change in the motion of a moving object
– Unbalanced forces = net force is greater than zero
• Object will move in the direction of greater force
Friction
• A force that opposes motion between two surfaces that are in contact– Static friction: surfaces are stationary– Kinetic friction: surfaces are moving
Static friction is usually greater than kinetic friction.
Kinetic Friction
• Different kinds:– Sliding Friction: Object slide past each other– Rolling Friction: Round object rolls over flat
surface
Rolling friction is usually less than sliding friction.– Fluid Friction: Object moving through a fluid