Three conductors meet at a junction

PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits

Problem

Three conductors meet at a junction. The current in wire P enters the junction and varies with time according to

I_P(t)=0.40t\,(\text{A})

, where

t

is in seconds. The current in wire Q leaves the junction at a constant

1.2\,\text{A}

. Taking currents that leave the junction as positive, derive an expression for the current

I_R(t)

in wire R.