A steel anchor with a weight of 3950 N is at the bottom of the river. What force must be applied to the chain to lift it?

To determine the force required to lift the steel anchor under consideration from the bottom of the river, we apply the formula: F = Ft – Fa = P – ρw * g * V = P – ρw * g * m / ρst = P – ρw * g * Р / ( ρst * g) = P – ρw * P / ρst = P * (1 – ρw / ρst).

Constants and variables: P – weight of the steel anchor (P = 3950 N); ρw is the density of river water (ρw = 1000 kg / m3); ρst is the density of steel (ρst = 7800 kg / m3).

Calculation: F = P * (1 – ρw / ρst) = 3950 * (1 – 1000/7800) = 3443.6 N.

Answer: A force of 3443.6 N must be applied to the circuit.