The rate of heating is 2.0 kW. Calculate how much energy is supplied to the substance during the period 18 – 22 minutes.

an electric circuit

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

i think it would be 5