To determine the specific heat of an oil, an electrical heating coil is placed in a calorimeter with 380 g of the oil at 10 °C. The coil consumes energy (and gives off heat) at the rate of 84 W. After 3.0 min, the oil temperature is 40 °C. If the water equivalent of the calorimeter and coil is 20 g, what is the specific heat of the oil?