A cylindrical metal can with a radius of 4.25 cm is floating upright in water. A rock is placed in the can, causing it to sink 0.0230 m deeper into the water. What is the weight of the rock?

Answer 1

The mass of additional water displaced equals the mass of the rock.

That equals
pi*R^2*2.3 cm^3* 1.00 g/cm^3 = 65.3 grams = 0.0653 kg

For the rock's weight in newtons, multiply that by 9.8.