force, motion and work. how do you know if an object is moving or is at rest?

Force, Motion and Work

How do you know if an object is moving or is at rest?

You observe that object in relation to another object. This is called FRAME OF

REFERENCE.

Frame of ReferenceFrom a sidewalk, you would see a bus

moving.Riding on a bus, you would be still unless you got up and moved on the bus.

How does your frame of reference affect your perception of

movement when you are in a moving vehicle?

Force

Force is a push or a pull that acts on an

object.When have you ever pushed or pulled anything?

Was it easy or difficult?Why was it easy or difficult?

Turn and discuss with a neighbor…..

Balance and Unbalanced Forces

Balanced Forces•When the forces are equal, the 2 forces

cancel each other out•Balanced forces do not cause a change in

motion.•Balanced forces are equal in strength.

Unbalanced Forces•Unbalanced forces cause a change in motion.

• The forces are unequal.•The strongest force exerted determines the

direction of the force.•The difference between the 2 forces is called

the net force.