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How do forces affect motion? Adapted by Diane Gioia Bell’s Crossing Elementary. Forces always work in pairs. One force pushes in one direction, and the other pushes with equal strength in the opposite direction.
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How do forces affect motion?Adapted by Diane GioiaBell’s Crossing Elementary
One force pushesin one direction, and the other pushes with equal strength in the opposite direction.
Walking demonstrates action and reaction becauseone foot pushes on the ground as the ground pushes the body forward.
Earth pushes forward against your foot with an equal reaction force.
Forces A push or pull is called a force and forces make things move faster or slower, stop, change direction, or change size and shape.
Types of Forces Magnetism A force that acts at a distance and cannot be seen. The closer the objects, the greater the magnetic force. The needle of a compass moves because of Earth’s magnetism.
Magnetism Materials that create this force are said to be magnetic and are called magnets. The closer the objects, the greater the magnetic force.
Types of Forces Friction: The force that opposes motion between two surfaces that are touching.
Types of Forces Friction http://pals.sri.com/tasks/9-12/Fricforce/icongif/friction.GIF
Friction The rougher the surfaces are, the harder they press together, the more friction there will be.
A smooth surface allows you to go faster, while a rough surface would be easier to stop on.
Friction • Occurs between liquids and gases as well as between solids. • Without friction you would not be able to slow or stop the motion of objects.
Loss of Friction http://www.school-for-champions.com/science/images/friction_uses-bear.jpg
Friction Friction can be reduced by using lubricants, for example motor oil, wax, grease, by making surfaces smoother, or by using rollers.
Lubrication Lubrication, for example, oil or grease, reduces the effects of friction. Without lubrication, moving parts of machines would slow down or stop very quickly.
Types of Forces How does gravity affect motion?
Gravity What do you think it is?
Gravity is a force that makes any object attract, or pull toward, another object.
All objects, large and small, pull on all other objects. Gravity
Gravity • The attraction is not noticeable unless one of the objects is very large. Earth is so big it keeps everything on the ground.
http://svideo.greenville.k12.sc.us/videos/11883/chp898138_256k.asfhttp://svideo.greenville.k12.sc.us/videos/11883/chp898138_256k.asf • Introduction to forces and gravity 3:20 • Some types of forces (for review) • Types of Force