* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Force and Motion
Survey
Document related concepts
Center of mass wikipedia , lookup
Jerk (physics) wikipedia , lookup
Brownian motion wikipedia , lookup
Coriolis force wikipedia , lookup
Fictitious force wikipedia , lookup
Length contraction wikipedia , lookup
Modified Newtonian dynamics wikipedia , lookup
Rigid body dynamics wikipedia , lookup
Classical mechanics wikipedia , lookup
Relativistic mechanics wikipedia , lookup
Newton's theorem of revolving orbits wikipedia , lookup
Centrifugal force wikipedia , lookup
Seismometer wikipedia , lookup
Equations of motion wikipedia , lookup
Hunting oscillation wikipedia , lookup
Classical central-force problem wikipedia , lookup
Transcript
Potential vs. Kinetic Potential * GPE * stored energy * not moving * the higher the object the more PE * GPE=mgh G= 9.8 m/s2 Kinetic * KE * energy of motion * moving * the faster an object the more KE * KE=mv2 Mechanical vs. Chemical Mechanical Chemical • ME = PE+KE • Physical change • Only changes the physical appearance • Ex. Gears moving in a car • Energy that is moving * Chemical change * changes the composition * Ex. food being broken down * energy that is stored Types of Energy Electrical: energy that is transferred by electrical charges or current Sound: associated with vibrations of matter and requires an object to travel through (Medium). Ex. Water Solar: the energy given off by the sun Chemical: energy that is stored in the chemical composition of matter Thermal: the energy given off my heat Light: energy given off by light Nuclear: the potential energy stored in the nucleus of an atom Simple Machines Type Definition Example Lever A solid bar that rotates around a fulcrum Inclined Plane A flat horizontal or sloped ramp Pulley A wheel that turns on an axle Handicap ramp Crane, gears Wheel & Axle A wheel that is fixed to a pulley Car or gears Wedge 2 incline planes that are together screwdriver Screw An incline plane wrapped around a shaft Spiral stairs or meat grinder Wheelbarrow Illustration Force and Motion Important Terms Position: location (can be an object or place) Reference Point: location that you compare your object or place’s position Motion: change of position over time Speed: the measure that something moves in a given amount of time s=distance over time Velocity: speed in a specific direction Acceleration: the rate at which velocity changes with time Force and Motion Important Terms Friction: force that resists the motion between two surfaces in contact. Force: a push or pull (F= M x A) Balanced force: net force is zero, the motion of an object does not change Unbalanced force: changes the motion of an object Inertia: the resistance of an object to a change in the speed or direction of its motion Newton’s st 1 Law of Motion An object at rest stays at rest, and an object in motion stays in motion at the same velocity, unless acted upon by an unbalanced force. Newton’s First Law is also called the Law of Inertia. Inertia is closely related to mass. When you measure the mass of an object, you are also measuring its inertia. The more mass something has, the harder it is to change its motion. Ex: It’s easier to stop an empty wagon than a wagon full of sand. nd 2 Law of Motion Acceleration of an object increases with increased force and decreases with increased mass. The direction in which an object accelerates is the same as the direction of the force. Simply put: Newton’s Second Law is… F = ma (Force = mass x acceleration) The standard unit of force is the newton (N). Because force = mass x acceleration, force is measured in units of mass (kg) times units of acceleration (m/s2). A newton is the amount of force that it takes to accelerate 1 kg of mass 1 m/s2. So…. I N = 1 kg x 1 m/s2. rd 3 Law of Motion Forces always act in pairs! Newton’s Third Law: For every action, there is an equal and opposite reaction. Every time one object exerts a force on another object, the second object exerts a force that is equal in size and opposite in direction back on the first object. Summary of Newton’s 3 Laws Distance/Time Graphs The motion of an object can be represented in a line graph. The data table below charts the motion of an object in 20 seconds. Construct a line graph on page 28 (blank page) that shows the motion of the object. Be sure to label both axes. Then, use the graph to describe the motion of the object between 0 and 10 seconds. Distance vs. Time Time (s) 0 5 10 15 20 Distance (m) 0 10 10 15 20