Question

If the water displaced by an object has a volume of 0.1 m3, what is the buoyant force exerted

on that object?

Answer 1

Approximately
`1000 \; {\rm N}` (assuming that
`g = 10\; {\rm N \cdot kg^(-1)}`.)

Step-by-step explanation:

The buoyant force on an object is equal to the weight of the liquid that this object has displaced.

In this example, the object displaced
`V = 0.1\; {\rm m^(3)}` of water. The density of water is
`\rho = 1.00 * 10^(3)\; {\rm kg \cdot m^(-3)}`. Thus, the mass of the water displaced would be
`m = \rho\, V = 1.00 * 10^(2)\; {\rm kg}`.

Since
`g = 10\; {\rm N \cdot kg^(-1)}` by assumption, the weight of that
`m = 1.00 * 10^(2)\; {\rm kg}` of water would be
`m\, g = 1.00 * 10^(3)\; {\rm N}`. Hence, the buoyant force on this object would be
`1.00 * 10^(3)\; {\rm N}`, which is
`1000\; {\rm N}` when rounded to one significant figure (as in volume.)