AP Physics Unit 3

Translation

Change in Position

Kinetic

refers to motion (scalar)

k=(1/2)mv²

Kinetic Energy equation

System

Object/collection of objects

Work

Amount of mechanical energy transferred into or out of a system

Constant Work

No work is leaving or entering the system

W=Fdcosϴ

Equation for work

Conservative forces

path independent work; only depends on initial and final configurations (gravity); associated it with potential energy

Non-conservative forces

path dependent work (friction/air resistance); normally opposes object’s path

Work

Area under curve of force and distance graph

Work energy theorem

Work done on an object such that force put on an object is equal to change in energy (KE) (ΔK=Fdcosϴ)

Elastic potential energy

potential energy of an ideal spring (U_s=(1/2)K(Δx)²)

F=kx

Spring Constant

Gravitational potential energy

PE associated with the position of an object in a gravitational field (U_g of the “Object Earth system)

U_g=mgy

Gravitational PE equation

U_g=(G (m1) (m2))/ r

U_g on a larger scale

Conservation of energy

energy can’t be created or destroyed, only transformed; total energy remains constant (without non-conservative forces)

Power

rate at which work is done/rate wat which energy changes

P= W/Δt = ΔE/Δt

Formula for power