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Forces. SOL 4.2 (Information Used from www.solpass.org). Force. A force is a push or a pull. Every time you push or pull something you use a force. Forces transfer energy. Energy.
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Forces SOL 4.2 (Information Used from www.solpass.org)
Force • A force is a push or a pull. Every time you push or pull something you use a force. Forces transfer energy.
Energy • When you throw a ball, the force of your arm pushes the ball into the air. Energy is transferred from your arm to the ball.
Potential Energy • Stored energy • Energy on hold and ready to go
Push and Pull • A pull that starts an object moving might be the pull of gravity or the pull of a magnet. A push that starts an object moving might come from the wind or the muscles in your legs. • Once it is moving it has kinetic energy.
Inertia • An object in motion will stay in motion, until a force stops it. The force stopping the object's motion might be an obvious one - the ground! • An object at rest will stay at rest, until a force starts it moving.
Friction • A less obvious force that stops or slows motion is friction. Even air causes friction. Friction is a force that prevents or stops motion. Friction is the resistance to motion created by two objects moving against each other (the sled and the snow). Friction creates heat. (rub your hands together)
Mass and Inertia • How a force affects an object depends on the object's mass. The more massive an object, the less effect a given force will have on the object. More massive objects are said to have more "inertia".
Quiz Time #1 • Which shoe tread would provide the most friction to keep you from slipping? • A. --C. • B. --D. Correct Answer-A
Quiz Time #2 • Objects in motion have ______________ energy. • A. Stored • B. Kinetic • C. Potential • D. Negative Correct Answer-B
Quiz Time #3 • Due to the pull of gravity, the higher an object is off the ground, the more _________________ energy it has. • A. Kinetic • B. Electrical • C. Chemical • D. Potential Correct Answer-D
Quiz Time #4 • When an apple is hanging on a tree it has potential energy. When it falls off the tree, potential energy changes to: • A. Chemical Energy • B. Kinetic Energy • C. Nothing • D. Electrical Energy Correct Answer-B
Quiz Time #5 • In order to move a piano that weighs 800 pounds, you will have to produce more or less force than moving a piano that weighs 400 pounds. 800 lbs 400 lbs Correct Answer-more force
Quiz Time #6 • You are having a hard time getting a ring off of your finger. What could you do to reduce the amount of friction to help you remove the ring? • A. Rub the ring with a cloth • B. Have a friend pull as hard as they can • C. Put baby powder on the ring • D. Put oil on the ring Correct Answer-D