Step 1: Understand restoring forces.
Heave (vertical motion) and Pitch (rotation about transverse axis) have inherent restoring forces due to buoyancy and weight acting through different points.
Step 2: Surge and sway.
Surge (longitudinal) and sway (lateral) motions do not inherently have restoring forces unless influenced by external constraints.
A negligibly thin horizontal plate PQ has a length 3 m and width 1 m. It is being pulled along its length at a speed of 1 m/s in between two static parallel plates as shown in the figure. The gap of 6 cm between the plates is filled with a Newtonian fluid of dynamic viscosity \( \mu = 0.2 \, {N-s/m}^2 \). The thin plate is located at 3 cm from the top surface. The velocity distribution between the thin plate and the static plates is linear.
The steady force required to pull the plate is __________ N (answer in integer).
Match the non-dimensional numbers in Column 1 with the corresponding definitions in Column 2:
A closed system is undergoing a reversible process 1–P–2 from state 1 to 2, as shown in the figure, where X and Y are thermodynamic properties. An irreversible process 2–Q–1 brings the system back from 2 to 1. The net change in entropy of the system and surroundings during the above-mentioned cycle are _______ respectively.
A ship of 3300 tonne displacement is undergoing an inclining experiment in seawater of density 1025 kg/m\(^3\). A mass of 6 tonne is displaced transversely by 12 m as shown in the figure. This results in a 0.12 m deflection of a 11 m long pendulum suspended from the centerline. The transverse metacenter of the ship is located at 7.25 m above the keel.
The distance of the center of gravity from the keel is ________ m (rounded off to two decimal places).
A multi-cell midship section of a ship with \( B = 40 \, {m} \) and \( D = 20 \, {m} \) is shown in the figure. The shear-flows are given as \( q_1 = q_2 = q_3 = 0.9376 \, {MN/m} \). The applied twisting moment on the midship section is ___________ MN·m (rounded off to two decimal places).
Consider a weightless, frictionless piston with a 2 kg mass placed on it as shown in the figure. At equilibrium in position 1, the cylinder contains 0.1 kg of air. The piston cross-sectional area is 0.01 m2. The ambient pressure in the surroundings outside the piston-cylinder arrangement is 0 bar (absolute). When the mass above the piston is removed instantaneously, it moves up and hits the stop at position 2, which is 0.1 m above the initial position.
Assuming \( g = 9.81 \, {m/s}^2 \), the thermodynamic work done by the system during this process is ________ J (answer in integer).