If an object that floats on the surface desplaces 10 cm3 of water how much does that object weigh?

By Archimedes' Principle, a floating body displaces a volume of fluid whose weight is exactly equal to its own.

• This assumes that the body is in equilibrium.
• In order to know the weight of the body (i.e. the object) you must know the density of the fluid in which it is floating.
• Also, Surface Area (SA, in cm2) of object must be known.
• Suppose density of the fluid is rho.

Thus,

Having height = 10cm

Wobject = Volumedisplaced*Densityfluid = SA*Height*rho

Suppose it is water with rho = 1g/cm3, SA = 1cm2

Wobject = 10cm*1cm2*1g/cm3 = 10g.

Just make sure your units are correct.