BELLRINGER

Free Response Help August 30- Day 1 1980 B1 1981 B1 1986 B1

Forces Newton’s 3 Laws Vector Addition 1) Law of Inertia: objects at rest will stay at rest and objects in motion will stay in motion unless acted on by an outside force “inertia” is NOT a force but a RESULT of an object’s mass If VELOCITY is constant, then there is NO NET force 2) The acceleration of an object is directly proportional to the NET force acting on it ∑F net = manet 3) For every action, there is an equal an opposite reaction Vector Addition The resultant is the sum of the x & y components Can solve for using Pythagorean Theorum

Forces Springs When a spring is stretched or compressed from its unstressed length by a distance x , the law is F = kΔx Where k is the “spring constant” This is unique to each spring

New Concepts & Equations ∑F = ma f = µN Work is the amount of force done over a distance W = Fd Work = (force )(distance) Kinetic Energy is the energy of motion Work also corresponds to the CHANGE in kinetic energy so… ΔKE = (Fnet )( d )

Work Problems

Energy Law of Conservation of Energy: in all cases, energy can not be created or destroyed--only transformed This means our initial energy = final energy The TOTAL energy of something looks at both kinetic and potential KE = If it’s moving with a velocity =1/2mv2 PE= The position off the ground= mgh (where h is height) KEi + PEi = KEf + PEf 1/2mvi2 + mghi = 1/2mvf2 + mghf

Centripetal Force