1. The problem statement, all variables and given/known data If at some particular place and time the sun light is incident on the surface of the earth along a direction defined by the unitary vector – vˆ , where vˆ =(4, 3, 5)/sqrt (50) and with a power density P, what is the total power captured by a solar panel of 1.4 m2 and with an efficiency of 12% which is oriented along the vector wˆ =(0, 1, 4) /sqrt(17) ? 2. Relevant equations The dot/scalar product equation. 3. The attempt at a solution I took the scalar product of -v and w, this gave me -23/sqrt(50*17), then multiply this by P*1.4*0.12, but my question is that the overall answer I get is negative due to the dot product. Is this possible as total power ? and am I doing this correctly ?.