Question

An early submersible craft for deep-sea exploration was raised and lowered by a cable from a ship. When the craft was stationary, the tension in the cable was 5500 N. When the craft was lowered or raised at a steady rate, the motion through the water added an 1800 N drag force.What was the tension in the cable when the craft was being lowered to the seafloor?

Answer 1

`T = 12910.5\,N` for a craft with a mass of 1500 kg.

Step-by-step explanation:

Let consider that craft has a mass of 1500 kg. The submersible craft is modelled after the Newton's Laws, whose equation of equilibrium is:

`\Sigma F = T - W +F_(D) = 0`

The tension experimented by the cable while the craft is lowering to the seafloor is:

`T = W - F_(D)`

`T = (1500\,kg)\cdot \left(9.807\,(m)/(s^(2)) \right)-1800\,N`

`T = 12910.5\,N`