MAGNETISMThe force-that pullsand attractsobjects madeof iron andsteel towardsa magnet
MAGNETIC NONMAGNETICMATERIALS MATERIALS• tin cans • paper• Iron nails • wood• needles • glass• safety pins • rubber • cloth • plastic
What are the forces we discussed?• Wind• Water• Gravity• Magnetism
BALANCED AND UNBALANCED FORCES• When the forces acting on an object are balanced, there is no motion• When the force acting on an object is not balanced, motion takes place Let’s try it!
INERTIA• The tendency of an object to remain at rest or resist a change in motion due to some external forces. HOW THIS HAPPENS?
ACTION AND REACTION• For every action, there is an equal and opposite reaction. SHOW IT HOW!
KEY POINTS• Force is a pull or a push.• There are different forces that make objects move:-wind, water, gravity, magnetism.• Unbalanced forces cause objects to move• Inertia is the tendency of an object to remain at rest, or to keep moving in the same direction unless an outside force acts on it.• For every action, there is an equal and opposite reaction.
ANSWER ME!• Why should you hold on tightly when riding a bus?• You need a wind to blow to fly your kite up the sky. When the wind stops blowing, what happens to the kite? Why?
True or False ____ 1. Force is needed to make things move ____ 2. Running water has force that can move things ____ 3. The farther away from the center of the earth, the stronger the pull of gravity. ____ 4. A magnet pulls or attracts wood and plastic. ____ 5. For every action, there is equal and opposite reaction.
ASSIGNMENT• Do activities on pages 255 and 257.