A ship moving through water will not only experience drag forces due to the viscosity of the water and air but also because it generates waves. Waves occur when water is accelerated upwards by the ship's motion and then accelerated downwards by gravity. Sea Water: density p = 1024 kg m-, viscosity = 1.4 x 10- kg m5. Use Buckingham Pi theory to determine dimensionless groups and show that one of the groups involves gravity, g, the ship's size (length), L, and the velocity, U.