[ld.mclemore]

A scale reads 100N when a piece of aluminum is hanging from it. What does it read when it is lowered so that the aluminum is submerged in water?

[ballengerb1]

It isn't quit that simple. You need to know more about the water. Temp and salt content will alter your reading but always be less than 100n. Bouyancy: Archimedes Principle

[ebaines]

All you really need to know is how the density () of the water compares to the density of the aluminum. Yes, these densities depend on things like temp (to a small extent) - but I suspect the OP has been given values for these in his/her text book.

The weight registered by the scale will be equal to: