AP physics Unit 4

• gravitational energy: $Ug=$$mgΔy$
• Kinetic Energy: $K=$$(1/2)mv²$
• Elastic(spring) energy: $Us=$$(1/2)KΔx²$

  K = spring constant (N/m)
• Hookes law: $Fs =$$KΔx$
• Work: $W=$$ΔE=$$Fd$

  unit: Nm or joules
• Power: $P=$$ΔE/Δt=$$FV$

  unit: watts
• Conservation of energy in closed system: all energy is conserved within the system, E1=E2
• Conservation of energy in open system: the system energy will change based on work done on/by the system, E1=E2+W