HELP PLEASE solar panels are used to gather energy to heat a swimming pool

A. chemical to radiant
B. mechanical to thermal
C. thermal to nuclear
D. radiant to thermal

Asimply means that over time there was some sort of change.

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?