Non-conservative work and mechanical energy (W_nc = ΔE)

jee-mainjee-advancedneet-ug

W_nc = ΔE

What each symbol means

SymbolWhat it stands for
EMechanical energy K+U for chosen conservative U definitions (J)
W_ncWork by non-conservative forces (friction, tension with slip, etc.) (J)

When to use this

Conservative forces already encoded in U; W_nc is work by forces not represented in potential energy.