PhysicsMotion, Speed, Velocity,acceleration, & energy
Motion 1 What is motion? How do you know if something is “in motion?”
Motion 2 Motion is the changing distance between two objects. You can tell if something is “in motion” based on a reference point. Reference point: A place or object used for comparison to determine if something is in motion.
Motion 3 Are we moving right now? Yes? No? How do you know? What is your reference point? **Technically, we are doing both moving AND not moving depending on your reference point!
Speed 1 What is speed? How do you know what “speed” you are going? Is speed fast or slow? Or both?
Speed 2 Speed is the amount of distance an object travels in any given amount of time. We calculate speed like this: Speed = Distance / Time Average speed is just: total distance / total time
Velocity 1 What is velocity? Is velocity the same thing as speed? How do I know what an objects velocity is?
Velocity 2 Velocity is speed with direction. When dispatch contacts a police officer to let them know where a suspect is, they will give them a velocity: “the perpetrator is on walnut st. traveling at 40mph north.” What else do we use velocity to describe?
Velocity 3 Change in velocity can be due to two things: 1. Change in speed 2. Change in direction (it can be only one or both)
Acceleration 1 What is acceleration? What does it mean to accelerate? What is the opposite of accelerate?
Acceleration 2 Acceleration is the rate at which velocity changes with time. If velocity requires both speed and direction, then acceleration also requires both speed and direction. Therefore… acceleration refers to increasing speed, decreasing speed or changing direction!
Acceleration 3 Increasing speed: When an objects speed increases, it is accelerating. Decreasing speed: When an objects speed decreases, it is deccelerating or has negative acceleration. Changing direction: If the direction changes so does the acceleration- even if the speed stays the same!!!
Acceleration 4 Calculating acceleration: you must figure out the change in velocity per unit time.Acceleration= Final velocity - Initial Velocity timeThe units used for Acceleration are meters per second per second or m/s 2
Energy Energy is the ability to do work or cause change. When a living thing does work on another object, some of that energy is transferred. Examples?
Kinetic Energy 1 Kinetic energy is the energy an object has due to its motion; this depends on both it’s mass and it’s speed. More mass means more kinetic energy More speed means more kinetic energy Examples?
Kinetic Energy 2 Calculating Kinetic Energy:Kinetic Energy = 1/2 x Mass x Speed 2Note- changing the speed has a greater impact on the object’s kinetic energy than changing the mass.
Potential Energy 1 Potential Energy is stored energy that results from an objects position or shape. This object has the potential to do work. When the object was placed where it is or shaped a certain way, energy was transferred to it. Examples?
Potential Energy 2 Gravitational Potential Energy is an objects potential energy based on gravity. This is dependant on its height relative to a reference point and it’s weight. Elastic Potential energy is the potential energy of an object that can be stretched or compressed
Law of Conservation of Energy According to the law of conservation of energy, energy cannot be created or destroyed. (sound familiar? What is another law that is similar to this?)