You measure the power delivered by a battery to be 1.15 W when it is connected in series with two equal resistors. How much power will the same battery deliver if the resistors are now connected in parallel across it

The power is  

Explanation:

From the question we are told that

   The power delivered is  

   Let it resistance be denoted as R

    The resistors are connected in series so the equivalent resistance is  

Considering when it is connected in series    

Generally power is mathematically represented as

Here I is the current which is mathematically represented as

The power becomes

substituting value

Considering when resistance is connected in parallel

  The equivalent resistance becomes

So The current  becomes

And the power becomes

 substituting values

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