Assuming they start at the same temperature, which will heat up faster, a swimming pool or a bathtub? Why?

Not an expert opinion but probably a bath tub bc that is pure water but pool water consists of chlorine making it thicker and flammable so it will take more time as it is more viscous and requires more heat

I’m no expert this is just from research,

“The more material, the more energy needs to be added to invoke a temperature change. Since the swimming pool contains more molecules, and there for more mass, more energy needs to be added to have the same temperature change as that of a bathtub. The bathtub will heat faster.”

It’s b. mass i searched it up