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## Homework Statement

On land, the maximum weight of a concrete block you can carry is 25kg. How massive block could you carry underwater, if the density of concrete is 2200kg/m³?

p

_{water}= 1000 kg/m³

p

_{concrete}= 2200 kg/m³

m1 = 25 kg

m2 = ?

G = mg

g = 9,81 m/s²

## Homework Equations

Archimedes' Principle

F

_{applied}- G + F

_{buoyancy}= 0

G - F

_{buoyancy}

## The Attempt at a Solution

Approach 1:

F

_{applied}- G + F

_{buoyancy}= 0 ->

m

_{1}g - m

_{2}g + m

_{2}p

_{water}g / p

_{concrete}= 0

And I come to this:

m

_{2}= -m

_{1}/ ( (p

_{water}/p

_{concrete}) - 1 )

m

_{2}= 45,8333..... kg

Approach 2:

On land I need (F= mg) 245,25 N to carry the concrete block

G - F

_{bouyancy}= 245,25 N

m

_{2}g - m

_{2}g(p

_{water}/ p

_{concrete}) = 245,25N

m

_{2}g(1 - p

_{water}/ p

_{concrete}) = 245,25 N

m

_{2}= 245,25N / g(1 - p

_{water}/ p

_{concrete})

m

_{2}= 45,8333... kg