Forces - Gravity, Friction, and Magnetic Forces - PDF

Forces Chapter 2 (Gravity & Friction) Chapter 19 (Electric Forces) Chapter 20 (Magnetic Forces) Electric and Magnetic forces (Stemscopes) Gravitational Forces (Stemscopes)  The BIG Idea 1. How do forces change the motion of an object?  Lesson 1:...

Forces Chapter 2 (Gravity & Friction) Chapter 19 (Electric Forces) Chapter 20 (Magnetic Forces) Electric and Magnetic forces (Stemscopes) Gravitational Forces (Stemscopes)  The BIG Idea 1. How do forces change the motion of an object?  Lesson 1: Gravity and Friction Essential Questions: What are some contact forces and some non-contact forces? What is the law of universal gravitation? How does friction affect the motion of two objects sliding past each other?  What are the types of forces? Force: A push or a pull on an object Two Types of Forces: Contact Force A push or pull on Example: one object by Pushing a container another that is Pressing on touching it computer keys Friction Non-Contact A push or pull on Examples: Force one object by Gravity another that without Magnetic touching it Electrical  What are the 3 Types of Friction? pg. 49 Friction: A force that resists the motion of two objects that are touching Static Friction Prevents objects from sliding past each other Sliding Friction Sliding friction opposes the motion of objects sliding past each other Fluid Friction Friction between a surface and a fluid such as water or air ( air resistance)  Static Friction vs. Sliding friction Static Friction: Sliding Friction: + + Static friction Applied force Sliding Applied force -100N 100N friction 200N -70N Net Force = 0N Net Force =  How is gravity affected by mass and distance? Gravity: Is an attractive force that exists between all objects that have mass Mass: Amount of matter in an object Change in mass: The more the mass the Change in distance: The greater distance more gravitational pull the less gravitational pull  Weight vs. Mass Weight: The amount of gravitational force exerted on an object since weight is a force it is measured in newtons If an astronaut weighs 539N and has a mass of 55kg on Earth, what variable would change if she was on the moon? (F=ma) Her weight would be less because if her mass changed it would mean that she got thinner or flatter  Non-contact Force: Electrical pg. 679 Static Charge: Unbalanced positive or negative charge on an object. Opposite charges attract each other The same charges repel each other Variables that affect electric charge: Amount of charge: The more charge the greater the electrical force (attractive or repulsion). Distance: The more distance the less electrical force.  Non-contact Force: Magnetic Magnet: Object that attracts metal iron. Magnetic Pole: A place on a magnet where the force it applies is the strongest. Opposite poles (charges) attract each other The same poles (charges) repel each other Variables that affect magnetic strength: Size of the magnet Distance: The further away the magnets are the weaker the magnetic force