# A concrete slab with a volume of 2 m3 is submerged in water. What force must be applied to keep it in the water; in the air?

Given: V = 2 m3 pw = 1000 kg / m 5 rbet = 2300 kg / m3

Find: F1—?; F2 -?

In this task, we will face the interaction of two forces: the force of gravity and the force of Archimedes:

Fт = F2 = mg – gravity FА = рgV – Archimedes’ law

First, we find out what force must be applied to keep the stove in water:

F1 = Ft – FА = mg -pgV = rbetVg – pVg = gV (rbet -pv) = 10 • 2 • (2300 – 1000) = 10 • 2 • 1300 = 26000 N = 26 kN,

if we need a more accurate result, then we take g = 9.8 N / kg, then in the calculation we get a force equal to 25.5 kN.

Now let’s calculate the force that needs to be applied to keep the plate in the air:

P2 = pbet * g • V = 2300 • 9.8 • 2 = 45080 N = 45 kN

Answer: P1 = 25.5 kN; P2 = 45 kN

Given: V = 2 m3 pw = 1000 kg / m 5 rbet = 2300 kg / m3

Find: F1—?; F2 -?

In this task, we will face the interaction of two forces: the force of gravity and the force of Archimedes:

Fт = F2 = mg – gravity FА = рgV – Archimedes’ law

First, we find out what force must be applied to keep the stove in water:

F1 = Ft – FА = mg -pgV = rbetVg – pVg = gV (rbet -pv) = 10 • 2 • (2300 – 1000) = 10 • 2 • 1300 = 26000 N = 26 kN,

if we need a more accurate result, then we take g = 9.8 N / kg, then in the calculation we get a force equal to 25.5 kN.

Now let’s calculate the force that needs to be applied to keep the plate in the air:

P2 = pbet * g • V = 2300 • 9.8 • 2 = 45080 N = 45 kN

Answer: P1 = 25.5 kN; P2 = 45 kN