Ascale model of 1: 25 of a ship has a submerged area of 6 m2 a length of 5 m in which a drag force (ed) of 25 n is measured when an experiment is carried out in water with a speed of 1.2 m/s. calculate the total drag force in the prototype. remember that the total drag force is due to the friction forces plus the pressure forces. the friction force can be estimated by the following relationship where coefficient cf= 0.0735 /. assume that the dynamic viscosity is 0.001 pa-s and density of 1030 kg / both for the model and the prototype.

What difference(s) did you notice using a pneumatic circuit over hydraulic circuit. explain why the pneumatic piston stumbles when it hits an obstacle.

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.