Minimal Slack Notes on Physics Inertia- tendency of an object to maintain motion. Property of matter. Not Newton’s first law. Matter wants to maintain motion- moving objects want to stay in motion if stopped wants to stay stopped. Mass is measure of inertia. Things have mass because they have inertia. Units: keg Symbol m in equation.
Inertia is most constantly called rest mass but we call it mass because we are dealing with speeds not going to speed of light. Kinetic Energy- ‘+42 is proportional to K (or v is proportional to square root of K) mass is proportional to K K PROPORTIONAL TO NAVA Kinetic Energy is energy associated tit something in motion if it has velocity it has kinetic energy. Energy is scalar.
Change in energy can be negative when you go from set energy to loss In collision Units are Joules K=1/2 NVГ˜2 When something is written in speed and you need velocity for equation Just square the speed Joules equals keg times AMA/SAA Velocity has more effect on kinetic energy than mass. Still objects have no kinetic energy. Hint: Energy variables are capital Momentum proportional to mass and velocity p=NV Units= keg time m/s And is vector in as direction as velocity Conservation laws are applied in closed systems only
Collisions are closed Momentum is conserved///// total energy is conserved Momentum always conserved in collisions thus collision problems are sways momentum problems Total energy is always conserved Types of collisions: Elastic collisions Kinetic energy conserved Inelastic collisions Kinetic energy not conserved Total energy is conserved Perfectly inelastic collisions Special case where objects stick together after collisions- Kinetic energy goes into Deforming object that is colliding heat sound Change in momentum is impulse follows same rules Change in energy is if the energy is gained or lost by a system it is called Work W= hanged in energy (final- initial) Work can be negative If work is done on a system it increases total energy in system ( work will be positive) If work is done by a system it decreases the total energy ( work will be negative) Systems don’t lose energy in an inelastic collision but does lose kinetic energy thus the work is negative by the system Impulse= change in momentum change in p Types of energy: Energy (light)- vibrations of electromagnetic fields includes light outside of spectrum Electric energy- The movement of electrons ( electricity) Thermal Energy- The motion of atoms or molecules in a substance